#include <bits/stdc++.h>
#define GOOD_LUCK ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define int long long
#define itn int
#define endl "\n"
#define ff first
#define ss second
#define pb push_back
#define ppb pop_back
#define ins insert
#define lb lower_bound
#define ub upper_bound
#define bs binary_search
#define count1 __builtin_popcount
#define all(v) v.begin(), v.end()
using namespace std;
struct point{
};
int ctoi(char x) {
return (int)x - '0';
}
int sumab(int a, int b) {
return (a + b) * (b - a + 1) / 2;
}
int gcd(int a, int b) {
if (b == 0) return a;
return gcd(b, a%b);
}
int lcm(int a, int b) {
return a / gcd(a, b) * b;
}
void print(vector <int> &v) {
for (const int &i : v) cout << i << ' ';
}
constexpr int MAX = 1e+5 + 3, INF = 2e+9, MOD = 16714589, K = 18;
int temp, temp1, temp2, temp3;
vector <int> g;
pair<int, int> up[K+3][MAX];
void _() {
int n, q;
cin >> n >> q;
vector <int> v(n+1), dia(n+1);
for (int i=1; i <= n; i++) {
cin >> dia[i] >> v[i];
}
v[0] = dia[0] = INF;
g.assign(n+1, 0);
// build tree
// O(n * log(n))
multiset <pair<int, int>> ms;
ms.insert({dia[0], 0});
for (int i = n; i > 0; i--) {
auto it = ms.lb({dia[i]+1, 0});
g[i] = (*it).ss;
ms.insert({dia[i], i});
}
// correct
// build up
// O(n + n * log(n))
for (int i=1; i <= n; i++) {
up[0][i] = {g[i], v[i]};
}
up[0][0] = {0, INF};
for (int i=1; i <= K; i++) {
for (int j=1; j <= n; j++) {
if (up[i-1][j].ff == 0) {
up[i][j] = {0, INF};
}
else {
if (up[i-1][up[i-1][j].ff].ff == 0) {
up[i][j] = {0, INF};
}
else {
up[i][j].ff = up[i-1][up[i-1][j].ff].ff;
up[i][j].ss = up[i-1][j].ss + up[i-1][up[i-1][j].ff].ss;
}
}
}
}
// correct
// queries
// O(q * log(n))
while (q--) {
int x, y;
cin >> x >> y;
int l=0, r=n, ans = -1;
while (l <= r) {
int mid = (l + r) / 2;
int a = x, b = y-1;
bool c = 1;
for (int i = K-1; i >= 0; i--) {
if (mid & (1 << i)) {
if (b < up[i][a].ss) {
c = 0;
break;
}
b -= up[i][a].ss;
a = up[i][a].ff;
}
}
// cout << b << ' ' << mid << endl;
if (c) {
ans = a;
l = mid + 1;
}
else r = mid - 1;
}
cout << ans << endl;
}
}
signed main() {
GOOD_LUCK
int tests=1;
// cin >> tests;
while (tests--) {
_();
// cout << endl;
}
return 0;
}
// Problem X
// by Ekber_Ekber
/*
8 6
3 5
4 3
2 2
1 3
3 8
5 10
4 5
7 30
4 10
1 3
7 35
6 38
5 8
2 50
8 1
3 5
4 3
2 2
1 3
3 8
5 10
4 5
7 30
7 35
*/
