50分，后面全re求大佬帮忙

#include<bits/stdc++.h>
using namespace std;
const int N=10010;
int a[N], sum[N];
int ri,li,n,m;
int main()
{   cin>>n;
    for(int i=1;i<=n;i++)
    {cin>>a[i];
    sum[i]=sum[i-1]+a[i];}
    cin>>m;
    while(m--)
    {cin>>li>>ri;
    cout<<sum[ri]-sum[li-1]<<endl;}
    
    
    return 0;
    
}