# include <cstdio>
# include <iostream>
# define zero(x) ( (x) & (-x) )
# define nmax 1000005
using namespace std;
int S[nmax],n;
void update(int i,int x)
{
    for (;i<=n;i+=zero(i)) S[i]+=x;
}
int query(int i)
{
    int p=0;
    for (;i;i-=zero(i)) p+=S[i];
    return p;
}
int binar_search(int x)
{
    int p,u,m,s;
    for (p=1,u=n;p<=u;)
    {
        m=(p+u)/2;
        if (query(m)<x) p=m+1; else u=m-1;
    }
    if (query(p)==x) return p;
    return (-1);
}
int main(void)
{
    int m;
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d%d\n",&n,&m);
    int x,y,t;
    for (int i=1;i<=n;++i)
    {
        scanf("%d",&x);
        update(i,x);
    }
    while (m--)
    {
        scanf("%d",&t);
        if (t<2) scanf("%d%d",&x,&y);else scanf("%d",&x);
        if (!t) update(x,y);else
        if (t==1) printf("%d\n",query(y)-query(x-1));
        else printf("%d\n",binar_search(x));
    }
    printf("\n");
    return 0;
}