#include<bits/stdc++.h>
using namespace std;

const int maxN=(2e5)+5;

int lvl[maxN],euler[maxN],de;
vector<int> v[maxN];
int n,m,t[maxN];
int f[maxN],loga[maxN];
int rmq[20][maxN];
void dfs(int nod,int niv)
{
    lvl[nod]=niv;
    euler[++de]=nod;
    if(!f[nod]) f[nod]=de;
    for(auto it:v[nod])
    {
        dfs(it,niv+1);
        euler[++de]=nod;
    }
}

inline void buildrmq()
{
    for(int i=1;i<=loga[n];i++)
    {
        for(int j=1;j<n;j++)
        {
            if(j + (1<< (i-1) )>=n) rmq[i][j]=rmq[i-1][j];
                else
            {
                int nod1,nod2;

                nod1=rmq[i-1][j];
                nod2=rmq[i-1][j+ (1<< (i-1) ) ];
                if(lvl[euler[nod1]]<lvl[euler[nod2]]) rmq[i][j]=nod1;
                        else rmq[i][j]=nod2;
            }
        }
    }
}

inline int lca(int x,int y)
{

    if(f[x]>f[y]) swap(x,y);

    x=f[x];
    y=f[y];

    int len=(y-x+1);

    int l=loga[len];

    int nod1,nod2;

    nod1=rmq[l][x];

    int dif=len-(1<<l);

    nod2=rmq[l][x+dif];

    if(lvl[euler[nod1]]<lvl[euler[nod2]]) return euler[nod1];

    return euler[nod2];
}
int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);

    scanf("%d%d",&n,&m);

    for(int i=2;i<=n;i++)
    {
        scanf("%d",&t[i]);
        v[t[i]].push_back(i);
    }

    dfs(1,0);

    n<<=1;

  /*  for(int i=1;i<n;i++)
        printf("%d ",lvl[euler[i]]);
    printf("\n");*/

    for(int i=2;i<=n;i++)
        loga[i]=1+loga[i>>1];

    for(int i=1;i<n;i++)
        rmq[0][i]=i;

    buildrmq();
    //////
    while(m--)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        printf("%d\n",lca(x,y));
    }

    return 0;
}