#include <stdio.h>
#define NMax 100005
using namespace std;
int n,m,x,y,z,arb[4*NMax],val;
void _update(int pos)
{
    int bit = 0;
    while( pos <= n)
    {
        arb[pos] += val;
        while( ! (pos&(1<<bit)) )++bit;
        pos = pos + (1<<bit);
        ++bit;
    }
}
int _query(int pos)
{
    int bit = 0,suma = 0;
    while( pos > 0 )
    {
        suma = suma + arb[pos];
        while( ! (pos&(1<<bit)) )++bit;
        pos = pos - (1<<bit);
        ++bit;
    }
    return suma;
}
int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d %d",&n,&m);
    for(int i=1;i<=n;++i)
    {
        scanf("%d",&x);
        val = x;
        _update(i);
    }
    for(int i=1;i<=m;++i)
    {
        scanf("%d %d",&x,&y);
        if(x==0)
        {
            scanf("%d",&z);
            val = z;
            _update(y);
        }
        else if(x==1)
        {
            scanf("%d",&z);
            printf("%d\n",_query(z)-_query(y-1));
        }
        else if(x==2)
        {
            int suma = 0,p = 1,u = n,mij;
            bool gasit = false;
            while(p<=u)
            {
                mij = ((u+p)>>1);
                suma = _query(mij);
                if(suma<y)p = mij+1;
                else if(suma>y)u = mij;
                else
                {
                    gasit = true;
                    break;
                }
            }
            if(gasit)printf("%d\n",mij);
            else printf("-1\n");
        }
    }
    return 0;
}