大力出奇迹

#include <bits/stdc++.h>
using namespace std;
int n,a[1000],m,x,y;
int main(){
	scanf("%d%d",&n,&m);
	for(int i = 1;i<=n;i++)scanf("%d",&a[i]);
	while(m--){
		scanf("%d%d",&x,&y);
		int ans = 0;
		for(int i = x;i<=y;i++)ans+=a[i];
		printf("%d\n",ans);
	}
	return 0;
}