#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FOR(i, l, r) for (int i = (l); i <= (r); i++)
const int MAXN = 5 * 1e5 + 5;
const int INF = 1e18;
struct pii
{
int fi, se, idx;
bool operator<(const pii &other) const
{
return fi < other.fi; // Sắp xếp theo first, nếu cần thêm điều kiện khác thì bổ sung
}
};
int n, q, m;
int par[MAXN], up[MAXN][25], cost[MAXN][25];
pii a[MAXN], b[MAXN];
pii st[4 * MAXN];
void compress() {
vector<int> vals;
FOR(i, 1, n) {
vals.push_back(a[i].fi);
vals.push_back(a[i].se);
}
sort(vals.begin(), vals.end());
vals.erase(unique(vals.begin(), vals.end()), vals.end());
m = vals.size();
FOR(i, 1, n) {
a[i].fi = lower_bound(vals.begin(), vals.end(), a[i].fi) - vals.begin() + 1;
a[i].se = lower_bound(vals.begin(), vals.end(), a[i].se) - vals.begin() + 1;
}
}
void seg_init(int id, int l, int r) {
if (l == r) {
st[id] = {INF, INF, -1};
return;
}
int mid = (l + r) / 2;
seg_init(id * 2, l, mid);
seg_init(id * 2 + 1, mid + 1, r);
st[id] = min(st[id * 2], st[id * 2 + 1]);
}
void update(int id, int l, int r, int pos, int val, int idx) {
if (l == r) {
if (val < st[id].fi) st[id] = {val, val, idx};
return;
}
int mid = (l + r) / 2;
if (pos <= mid) update(id * 2, l, mid, pos, val, idx);
else update(id * 2 + 1, mid + 1, r, pos, val, idx);
st[id] = min(st[id * 2], st[id * 2 + 1]);
}
pii get(int id, int l, int r, int ql, int qr) {
if (ql > r || qr < l) return {INF, INF, -1};
if (ql <= l && r <= qr) return st[id];
int mid = (l + r) / 2;
return min(get(id * 2, l, mid, ql, qr), get(id * 2 + 1, mid + 1, r, ql, qr));
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> q;
FOR(i, 1, n) {
cin >> a[i].fi >> a[i].se;
a[i].idx = i;
b[i] = a[i];
}
compress();
seg_init(1, 1, m);
sort(a + 1, a + n + 1, [](pii x, pii y) { return x.fi < y.fi; });
FOR(i, 1, n) {
int u = a[i].idx;
pii t = get(1, 1, m, a[i].fi, a[i].se);
if (t.idx == -1) par[u] = u;
else par[u] = t.idx;
update(1, 1, m, a[i].se, a[i].fi, u);
}
FOR(i, 1, n) {
up[i][0] = par[i];
cost[i][0] = (par[i] != i ? 1 : 0);
for (int k = 1; k < 21; k++) {
up[i][k] = up[up[i][k - 1]][k - 1];
cost[i][k] = cost[i][k - 1] + cost[up[i][k - 1]][k - 1];
}
}
while (q--) {
int u, v;
cin >> u >> v;
if (u == v) {
cout << 0 << "\n";
continue;
}
if (b[u].se > b[v].se) {
cout << "impossible" << "\n";
continue;
}
int sum = 0, cur = v;
for (int k = 19; k >= 0; k--) {
if (b[up[cur][k]].fi > b[u].se) {
if (cur == up[cur][k]) {
sum = -1;
break;
}
sum += cost[cur][k];
cur = up[cur][k];
}
}
if (sum == -1) {
cout << "impossible" << "\n";
continue;
}
sum++;
if (b[u].se >= b[cur].fi && b[u].se <= b[cur].se) {
cout << sum << "\n";
continue;
}
cur = up[cur][0];
if (b[u].se >= b[cur].fi && b[u].se <= b[cur].se) {
cout << sum + 1 << "\n";
continue;
}
cur = up[cur][0];
if (b[u].se >= b[cur].fi && b[u].se <= b[cur].se) {
cout << sum + 2 << "\n";
continue;
}
cout << "impossible" << "\n";
}
return 0;
}
