#include <stdio.h>
#include <stdlib.h>

int main() {
    int N, M;
    scanf("%d %d",&N, &M);
    int* accSum = (int*)malloc(sizeof(int)*(N+1));
    accSum[0] = 0;
    for(int i=1; i<=N; i++){
        int n;
        scanf("%d",&n);
        accSum[i] += accSum[i-1] + n;
    }

    while(M--){
        int a, b;
        scanf("%d %d",&a, &b);
        printf("%d\n",accSum[b]-accSum[a-1]);
    }

    free(accSum);

    return 0;
}