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#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
const int maxn = 2e5 + 10;
typedef long long ll;
int a[maxn];
ll segment_tree[3 * maxn];

void build_segment_tree(int L, int R, int position) {
    if(L == R) {
        segment_tree[position] = a[L];
    }
    else {
        int mid = (L + R) / 2;
        build_segment_tree(L, mid, 2 * position);
        build_segment_tree(mid + 1, R, 2 * position + 1);
        segment_tree[position] = segment_tree[2 * position] + segment_tree[2 * position + 1];
    }
}
// L R i L R j L R
ll query(int L, int R, int position, int i, int j) {
    if(R < i or j < L) {
        return 0;
    }
    if(i <= L and R <= j) {
        return segment_tree[position];
    }
    int middle = (L + R) / 2;
    return query(L, middle, 2 * position, i, j) + query(middle + 1, R, 2 * position + 1, i, j);
}

int main() {
    ios_base::sync_with_stdio(false);
    int n, q;
    cin >> n >> q;
    
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }
    
    build_segment_tree(0, n - 1, 1);
    for(int i = 0; i < q; i++) {
        int x, y;
        cin >> x >> y;
        x--; y--;
        
        cout << query(0, n - 1, 1, x, y) << endl;
        
        
    }
    return 0;
}