include [HTML_REMOVED]
using namespace std;
int n,m;
const int N=10010;
int a[N],s[N];
int main()
{
ios::sync_with_stdio(false);
cin>>n>>m;
for(int i=1;i<=n;i) cin>>a[i];
for(int i=1;i<=n;i) s[i]=s[i-1]+a[i];//前缀和初始化
while (m–)
{
int L,r;
cin>>L>>r;
cout<<s[r]-s[L-1];
}
return 0;
}