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

int main() {
    int n;
    scanf("%d", &n);

    int *A = (int *)malloc((n + 1) * sizeof(int));
    int *prefix = (int *)malloc((n + 1) * sizeof(int));

    // Baca array (1-indexed)
    prefix[0] = 0;
    for (int i = 1; i <= n; i++) {
        scanf("%d", &A[i]);
        prefix[i] = prefix[i - 1] + A[i];
    }

    // Jawab query hingga sentinel -9
    int L;
    while (scanf("%d", &L) == 1 && L != -9) {
        int R;
        scanf("%d", &R);
        printf("%d\n", prefix[R] - prefix[L - 1]);
    }

    free(A);
    free(prefix);
    return 0;
}