#include <stdio.h>
#define MAX 100001
int n,m,tree[MAX];

void update(int idx,int val){
    while(idx<=n){
        tree[idx]+=val;
        idx+=idx&-idx; }
}

int read(int idx){
    int sum=0;
    while(idx>0){
        sum+=tree[idx];
        idx-=idx&-idx; }
    return sum;
}

int caut_bin(int sum){
    int st=1,dr=n,md,x;
    while(st<dr){
        md=(st+dr)/2;
        x=read(md);
        if(x>sum)dr=md-1; else
        if(x<sum)st=md+1; else return md; }
    return st==dr&&sum==x?st:-1;
}

int main(){
    int c,x,y;
    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);
            update(i,x); }
        for(int i=1;i<=m;i++){
            scanf("%d",&c);
        switch(c){
            case 0:
                scanf("%d %d",&x,&y);
                update(x,y);
                break;
            case 1:
                scanf("%d %d",&x,&y);
                printf("%d\n",read(y)-read(x-1));
                break;
            case 2:
                scanf("%d",&x);
                printf("%d\n",caut_bin(x));
                break; }
        }
}