#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define fi first
#define se second
#define cmin(a, b) a=min(a, b)
#define cmax(a, b) a=max(a, b)
void solve();
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
solve();
return 0;
}
int n, k, q;
vector<int> a;
void solve() {
cin >> n >> k;
a.resize(n); for (auto &u: a) cin >> u;
vector<int> pref=a; for (int i=1; i<n; i++) pref[i]+=pref[i-1];
set<pair<int, int>> st;
int act=0;
for (int i=0; i<n; i++) {
if (a[i]) act++;
else {
if (act) st.insert({i-act, i-1});
act=0;
}
}
cin >> q;
while (q--) {
int l, r; cin >> l >> r; l--, r--;
auto lb=st.lower_bound({r+1, r});
if (lb==st.begin()) {
cout << 0 << endl;
continue;
}
lb--;
if (lb->second==r) {
if (lb==st.begin()) {
cout << 0 << endl;
continue;
}
lb--;
}
int nb=max(0LL, pref[lb->second]-(l?pref[l-1]:0LL));
if (!nb || k==1) cout << nb << endl;
else cout << -1 << endl;
}
}
