#include<stdio.h>
int main()
{
int i,j,k,n,m, sum=0;
int num[1000001]={};
int arr[1000001][3]={};
scanf("%d %d", &n, &m);
for (i = 1 ; i <= n ; i ++)
{
scanf("%d", &num[i]);
}
for (i = 1 ; i <= m ; i ++)
{
scanf("%d %d", &arr[i][1], &arr[i][2]);
}
for (i = 1 ; i <= m ; i ++)
{
sum = 0;
for (j = arr[i][1] ; j <= arr[i][2] ; j ++)
{
sum += num[j];
}
printf("%d\n", sum);
}
}