#include <bits/stdc++.h>
using namespace std;
const int N=1e6+10;
const int INF=0x3f3f3f3f3f;
int n,m,a[N],s[N],x,y;
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
		s[i]=s[i-1]+a[i];
	}
	while(m--)
	{
		cin>>x>>y;
		cout<<s[y]-s[x-1]<<endl;
	}
	return 0;
}