#include <fstream>
using namespace std;

long long a[100000];
long long s[100000];

int main() {
    ifstream fin("ssm.in");
    ofstream fout("ssm.out");
    int n = 0;
    fin >> n;

    a[0] = 0;
    for (int i = 1; i <= n; ++i) {
        fin >> a[i];
    }
    s[0] = a[0];
    for (int i = 1; i <= n; ++i) {
        s[i] = s[i - 1] + a[i];
    }

    int st = 0;
    int dr = 0;

    for (int p = a[0]; p <= n; p++) {
        if (a[p] + a[p + 1] > 0) {
            a[p] = st;
            break;
        }
    }
    for (int p = st; p <= n; p++) {
        if (a[p] + a[p + 1] < 0) {
            a[p] = dr;
            break;
        }
    }

    int cnt_secv = 0;

    for ( int p = st; p <= dr; p++) {
        cnt_secv++;
    }

    for (int k = 1; k <= cnt_secv; ++k) {
        int i, j;
        fin >> i >> j;

        fout << s[j] - s[i - 1];
    }


    return 0;
}