#include<bits/stdc++.h> using namespace std; int main(){ int n,n2; int a[100],s[100]={}; cin>>n>>n2; for(int i=1;i<=n;i++) scanf("%d",&a[i]); while(n2){ int c,b; cin>>c>>b; for(int i=1;i<=n;i++) s[i]=s[i-1]+a[i]; cout<<s[b]-s[c-1]<<endl; n2--; } return 0; }