#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>

using namespace std;

/**

                                          `-.`'.-'
                                       `-.        .-'.
                                    `-.    -./\.-    .-'
                                        -.  /_|\  .-
                                    `-.   `/____\'   .-'.
                                 `-.    -./.-""-.\.-      '
                                    `-.  /< (()) >\  .-'
                                  -   .`/__`-..-'__\'   .-
                                ,...`-./___|____|___\.-'.,.
                                   ,-'   ,` . . ',   `-,
                                ,-'   ________________  `-,
                                   ,'/____|_____|_____\
                                  / /__|_____|_____|___\
                                 / /|_____|_____|_____|_\
                                ' /____|_____|_____|_____\
                              .' /__|_____|_____|_____|___\
                             ,' /|_____|_____|_____|_____|_\
,,---''--...___...--'''--.. /../____|_____|_____|_____|_____\ ..--```--...___...--``---,,
                           '../__|_____|_____|_____|_____|___\
      \    )              '.:/|_____|_____|_____|_____|_____|_\               (    /
      )\  / )           ,':./____|_____|_____|_____|_____|_____\             ( \  /(
     / / ( (           /:../__|_____|_____|_____|_____|_____|___\             ) ) \ \
    | |   \ \         /.../|_____|_____|_____|_____|_____|_____|_\           / /   | |
 .-.\ \    \ \       '..:/____|_____|_____|_____|_____|_____|_____\         / /    / /.-.
(=  )\ `._.' |       \:./ _  _ ___  ____  ____ _    _ _ _ _ _  _ __\        | `._.' /(  =)
 \ (_)       )        \/                                            \       (       (_) /
  \    `----'          """"""""""""""""""""""""""""""""""""""""""""""        `----'    /
   \   ____\__                                                              __/____   /
    \ (=\     \                                                            /     /-) /
     \_)_\     \                                                         /     /_(_/
          \     \                                                        /     /
           )     )  _                                                _  (     (
          (     (,-' `-..__                                    __..-' `-,)     )
           \_.-''          ``-..____                  ____..-''          ``-._/
            `-._                    ``--...____...--''                    _.-'
                `-.._                                                _..-'
                     `-..__       FORTIS FORTUNA ADIUVAT       __..-'
                           ``-..____                  ____..-''
                                    ``--...____...--''

*/

class parser{
    public:
        parser() {}
        parser(const char *file_name){
            input_file.open(file_name,ios::in | ios::binary);
            input_file.sync_with_stdio(false);
            index&=0;
            input_file.read(buffer,SIZE);}
        inline parser &operator >>(int &n){
            for (;buffer[index]<'0' or buffer[index]>'9';inc());
            n&=0;
            //sign&=0;
            //sign|=(buffer[index-1]=='-');
            for (;'0'<=buffer[index] and buffer[index]<='9';inc())
                n=(n<<1)+(n<<3)+buffer[index]-'0';
            //n^=((n^-n)&-sign);
            return *this;}
        ~parser(){
            input_file.close();}
    private:
        fstream input_file;
        static const int SIZE=0x400000; ///4MB
        char buffer[SIZE];
        int index/*,sign*/;
        inline void inc(){
            if(++index==SIZE)
                index=0,input_file.read(buffer,SIZE);}
};

class writer{
    public:
        writer() {};
        writer(const char *file_name){
            output_file.open(file_name,ios::out | ios::binary);
            output_file.sync_with_stdio(false);
            index&=0;}
        inline writer &operator <<(int target){
            aux&=0;
            n=target;
            if (!n)
                nr[aux++]='0';
            for (;n;n/=10)
                nr[aux++]=n%10+'0';
            for(;aux;inc())
                buffer[index]=nr[--aux];
            return *this;}
        inline writer &operator <<(const char *target){
            aux&=0;
            while (target[aux])
                buffer[index]=target[aux++],inc();
            return *this;}
        ~writer(){
            output_file.write(buffer,index);output_file.close();}
    private:
        fstream output_file;
        static const int SIZE=0x200000; ///2MB
        int index,aux,n;
        char buffer[SIZE],nr[24];
        inline void inc(){
            if(++index==SIZE)
                index&=0,output_file.write(buffer,SIZE);}
};

parser f ("lca.in");
writer t ("lca.out");

vector <int> v[100010];
vector <pair <int,int> > euler;
int RMQ[2][17][100010],index[100010],x,y;
bitset <100010> vaz;

void dfs(int nod,int level){
    vaz[nod]=true;
    euler.push_back({nod,level});
    index[nod]=euler.size()-1;
    for (auto i:v[nod]){
        if (!vaz[i])
            dfs(i,1+level);
        euler.push_back({nod,level});
        index[nod]=euler.size()-1;
    }
}

void magic(){
    vector <pair <int,int> >::iterator it=euler.begin();
    for (int i=0;it!=euler.end();++i,++it)
        RMQ[0][0][i]=it->first,
        RMQ[1][0][i]=it->second;
    for(unsigned i=0;i<16;++i)
        for(unsigned j=1;j<euler.size()-i;++j)
            if (RMQ[1][i][j]<RMQ[1][i][j+(1<<i)])
                RMQ[1][i+1][j]=RMQ[1][i][j],
                RMQ[0][i+1][j]=RMQ[0][i][j];
            else
                RMQ[1][i+1][j]=RMQ[1][i][j+(1<<i)],
                RMQ[0][i+1][j]=RMQ[0][i][j+(1<<i)];
}

void rmq(){
    int k=0;
    --x=index[x];
    --y=index[y];
    for(;(1<<k)<=(y-x+1);++k);
    --k;
    t<<1+(RMQ[1][k][x]<RMQ[1][k][y+1-(1<<k)]?RMQ[0][k][x]:RMQ[0][k][y+1-(1<<k)])<<"\n";
}

int main()
{
    int n,m;
    f>>n>>m;
    for (int x,i=1;i<n;++i)
        f>>x,
        v[x-1].push_back(i);
    dfs(0,0);
    magic();
    for (int i=0;i<m;++i)
        f>>x>>y,
        rmq();
    return 0;
}