#include <bits/stdc++.h>
using namespace std;
#define db(...) " [" << #__VA_ARGS__ << " : " << (__VA_ARGS__) << "] "
const int N = 100005;
int n, q;
int s[N], e[N], p[N];
namespace sub3 {
bool valid_input() {
return n <= 5000;
}
int dp[5005][5005];
void solve() {
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
dp[i][j] = 1e9;
}
}
queue<int> qu;
for (int i = 1; i <= n; ++i) {
while (qu.size()) {
qu.pop();
}
dp[p[i]][p[i]] = 0; // just to remember
qu.emplace(p[i]);
for (int j = i - 1; j >= 1; --j) {
int &res = dp[p[j]][p[i]];
while (qu.size() && s[qu.front()] > e[p[j]]) {
qu.pop();
}
if (qu.size()) {
res = min(res, dp[qu.front()][p[i]] + 1);
}
if (res != 1e9) {
qu.emplace(p[j]);
}
}
}
while (q--) {
int s, t;
cin >> s >> t;
if (dp[s][t] == 1e9) {
cout << "impossible\n";
} else {
cout << dp[s][t] << '\n';
}
}
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> q;
for (int i = 1; i <= n; ++i) {
cin >> s[i] >> e[i];
}
vector<int> ord(n);
iota(ord.begin(), ord.end(), 1);
sort(ord.begin(), ord.end(), [&](int x, int y) {
return e[x] == e[y] ? s[x] < s[y] : e[x] < e[y];
});
for (int i = 0; i < n; ++i) {
p[i + 1] = ord[i];
}
if (sub3::valid_input()) {
sub3::solve();
}
}
