#include "bits/stdc++.h"
using namespace std;
#ifdef duc_debug
#include "bits/debug.h"
#else
#define debug(...)
#endif
const int maxn = 3e5 + 5;
const int LG = 19;
int n, q;
int sl[maxn], sr[maxn];
int ord[maxn];
int up[maxn][LG + 1];
pair<int, int> tree[maxn << 2];
int lim;
void update(int pos, pair<int, int> val, int ind = 1, int l = 1, int r = lim) {
if (l == r) {
tree[ind] = min(tree[ind], val);
return;
}
int mid = (l + r) >> 1;
if (pos <= mid) update(pos, val, ind << 1, l, mid);
else update(pos, val, ind << 1 | 1, mid + 1, r);
tree[ind] = min(tree[ind << 1], tree[ind << 1 | 1]);
}
pair<int, int> get(int x, int y, int ind = 1, int l = 1, int r = lim) {
if (l > y || r < x) return make_pair(1e9, 1e9);
if (x <= l and r <= y) {
return tree[ind];
}
int mid = (l + r) >> 1;
return min(get(x, y, ind << 1, l, mid), get(x, y, ind << 1 | 1, mid + 1, r));
}
void solve() {
cin >> n >> q;
for (int i = 1; i <= n; ++i) {
cin >> sl[i] >> sr[i];
}
vector<int> cprs;
for (int i = 1; i <= n; ++i) {
cprs.push_back(sl[i]);
cprs.push_back(sr[i]);
cprs.push_back(sl[i] - 1);
}
sort(cprs.begin(), cprs.end());
cprs.erase(unique(cprs.begin(), cprs.end()), cprs.end());
lim = (int)cprs.size();
memset(tree, 0x3f, sizeof(tree));
for (int i = 1; i <= n; ++i) {
int l = lower_bound(cprs.begin(), cprs.end(), sl[i]) - cprs.begin() + 1;
int r = lower_bound(cprs.begin(), cprs.end(), sr[i]) - cprs.begin() + 1;
update(r, make_pair(sl[i], i));
}
for (int i = 1; i <= n; ++i) {
int l = lower_bound(cprs.begin(), cprs.end(), sl[i]) - cprs.begin() + 1;
int r = lower_bound(cprs.begin(), cprs.end(), sr[i]) - cprs.begin() + 1;
up[i][0] = get(l, r).second;
}
for (int j = 1; j <= LG; ++j) {
for (int i = 1; i <= n; ++i) {
up[i][j] = up[up[i][j - 1]][j - 1];
}
}
while (q--) {
int s, e; cin >> s >> e;
if (s == e) {
cout << 0 << '\n';
continue;
}
if (sr[e] < sr[s]) {
cout << "impossible\n";
continue;
}
if (sr[s] <= sr[e] and sr[s] >= sl[e]) {
cout << 1 << '\n';
continue;
}
int ans = 0;
int cur = e;
for (int i = LG; i >= 0; --i) {
if (up[cur][i] and sl[up[cur][i]] > sr[s]) {
ans ^= (1 << i);
cur = up[cur][i];
}
}
cur = up[cur][0];
++ans;
if (sl[cur] > sr[s] || sr[cur] < sr[s]) {
cout << "impossible\n";
continue;
}
cout << ans + (sr[s] >= sl[cur]) << '\n';
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
