#include<iostream>
#include<cmath>
#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;
int n,m,i,j,k,maxn=0,f[1001000],ok[1000100];
struct node{
    int s,t,w;
}a[1001000];
 
bool valid(int x){
    memset(f,0,sizeof(f));
    for(i=1;i<=x;++i){
        f[a[i].s]+=a[i].w;
        f[a[i].t+1]-=a[i].w;
    }
    j=0;
    for(i=1;i<=n;++i){
        j+=f[i];
        if(j>ok[i])return false;
    }
    return true;
}
int main(){
    memset(f,0,sizeof(f));
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;++i)scanf("%d",&ok[i]);
    for(i=1;i<=m;++i)scanf("%d%d%d",&a[i].w,&a[i].s,&a[i].t);
    if(valid(m)){printf("0\n");return 0;}
    int l=1,r=m;
    while(l<r){
        int mid=(l+r)/2;
        if(valid(mid)) l=mid+1;
        else r=mid;
    }
    printf("-1\n%d\n",l);
    return 0;
}

结果是20分: