#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
#define forin for(int i = 1; i <= n; i++)
#define stforin for(int i = 0; i < n; i++)
#define forim for(int i = 1; i <= m; i++)
#define forjn for(int j = 1; j <= n; j++)
#define forch(j, n) for(int i = j; i <= n; i++)
#define forch2(i, j, n) for(int i = j; i <= n; i++)
#define forjm for(int j = 1; j <= m; j++)
#define lol long long
#define lb long double
#define all(a) (x).begin(), (x).end();
#define endl '\n'
#define debug cout << "Completed" << endl;
#define fix(n, m) cout << fixed; cout.precision(b); cout << n << endl
#define Yes cout << "YES" << endl
#define No cout << "NO" << endl
#define bads cout << -1 << endl
#define pll pair<lol, lol>
#define mod 998244353
#define fst first
#define snd second
#define inf 1e15
#define tofix cin
; string sbuf;
ostringstream buf(sbuf);
istringstream atcin(sbuf);
lol gcd(lol a, lol b) {
while (a != 0 && b != 0) if (a > b) a %= b; else b %= a;
return a + b;
}
lol lcm(lol a, lol b) {
return a / gcd(a, b) * b;
}
bool issqrt(lol n) {
lb x = sqrt(n);
if (x == (lol)x) return 1;
return 0;
}
lol easy(lol n) {
if (n == 1) return 0;
for (int i = 2; i * i <= n; i++) if (n % i == 0) return 0;
return 1;
}
string bin(lol v) {
string ans;
while (v != 0) {
ans += to_string((v % 2));
v /= 2;
}
return ans;
}
//priority_queue <pll, vector<pll>, greater<pll>> q
const long long N = 2e5 + 100;
lol ts, n, q, c[N], d[N], r, v, pd, ans;
void solve() {
cin >> n >> q;
forin cin >> d[i] >> c[i];
forch2(_, 1, q) {
cin >> r >> v;
pd = -1;
for (ans = r; ans <= n && v > 0; ans++) {
if (d[ans] > pd) {
v -= c[ans];
pd = d[ans];
}
}
ans--;
if (v > 0) ans = 0;
cout << ans << endl;
}
}
int main() {
ts = 1;
//cin >> ts;
while(ts--) solve();
return 0;
}
