这道题开long long

#include <bits/stdc++.h>
using namespace std;
#define LL long long
const int N=1e6+10;
LL a[N],s[N];
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	LL n,m;
	cin>>n>>m;
	for(LL i=1;i<=n;i++) cin>>a[i];
	for(LL i=1;i<=n;i++) s[i]=s[i-1]+a[i];
	while(m--){
		LL x,y;
		cin>>x>>y;
		cout<<s[y]-s[x-1]<<'\n';
	}
	return 0;
}