/**
* In the name of Allah
* We are nothing and you're everything
**/
#include <bits/stdc++.h>
//#include "seats.h"
using namespace std;
using ll = long long;
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
//#define int ll
const char nl = '\n';
const int N = 1e6+10;
vector<int> r, c;
vector<int> R_mins, R_maxs;
vector<int> C_mins, C_maxs;
int h, w, p[N];
int ans;
void upd(int i) {
R_mins[i] = r[i];
R_maxs[i] = r[i];
C_mins[i] = c[i];
C_maxs[i] = c[i];
if (i > 0) {
R_mins[i] = min(R_mins[i], R_mins[i-1]);
R_maxs[i] = max(R_maxs[i], R_maxs[i-1]);
C_mins[i] = min(C_mins[i], C_mins[i-1]);
C_maxs[i] = max(C_maxs[i], C_maxs[i-1]);
}
int calc = (R_maxs[i]-R_mins[i]+1)*(C_maxs[i]-C_mins[i]+1);
if (calc == i+1) {
if (p[i] == 0)ans += 1, p[i] = 1;
} else {
if (p[i] == 1)ans -= 1, p[i] = 0;
}
}
void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
r = R, c = C;
h = H, w = W;
R_mins.assign(h*w, h*w);
C_mins.assign(h*w, h*w);
R_maxs.assign(h*w, 0);
C_maxs.assign(h*w, 0);
memset(p, 0, sizeof p);
for (int i = 0; i < h*w; ++i)
upd(i);
}
int swap_seats(int a, int b) {
swap(r[a], r[b]);
swap(c[a], c[b]);
if (a > b)swap(a, b);
for (int i = a; i <= b; ++i)
upd(i);
return ans;
}
//void solve() {
//int H, W, Q;
//cin >> H >> W >> Q;
//vector<int> R, C;
//R.resize(H*W); C.resize(H*W);
//for (int i = 0; i < H*W; ++i)cin >> R[i] >> C[i];
//give_initial_chart(H, W, R, C);
//while (Q--) {
//int a, b; cin >> a >> b;
//cout << swap_seats(a, b) << nl;
//}
//}
//int32_t main() {
//ios::sync_with_stdio(0);
//cin.tie(0);
//int t = 1;
//for (int _ = 0; _ < t; ++_) {
//solve();
//}
//return 0;
//}
