#include <iostream>
#include <set>
using namespace std;
const int maxn = 200005;
typedef long long ll;
const int INF = 2e9;
int n, a[maxn];

ll segment_tree[3 * maxn];

ll merge_nodes(ll A, ll B) {
return A + B;
}

void build_tree(int L = 0, int R = n - 1, int node = 1) {
if(L == R) {
segment_tree[node] = a[L];
}
else {
int middle = (L + R) / 2;
build_tree(L, middle, 2 * node);
build_tree(middle + 1, R, 2 * node + 1);
segment_tree[node] = merge_nodes(segment_tree[2 * node], segment_tree[2 * node + 1]);
}
}

ll query(int i, int j, int L = 0, int R = n - 1, int node = 1) {
if(R < i or j < L) {
return 0;
}
if(i <= L and R <= j) {
return segment_tree[node];
}

int middle = (L + R) / 2;
ll left_side = query(i, j, L, middle, 2 * node);
ll right_side = query(i, j, middle + 1, R, 2 * node + 1);

return merge_nodes(left_side, right_side);
}
int main() {
ios_base::sync_with_stdio(false);
int q;

cin >> n >> q;

for(int i = 0; i < n; i++) {
cin >> a[i];
}
build_tree();

for(int i = 0; i < q; i++) {
int a, b;
cin >> a >> b;

a--; b--;

cout << query(a, b) << endl;
}



return 0;
}