C++ :

#include <bits/stdc++.h>
using namespace std;
int n, k, x, y, w[1000005], a[1000005];
int main() {
	cin >> n >> k;
	while (k--) {
		cin >> x >> y;
		w[x]++;
		w[y + 1]--;
	}
	for (int i = 1; i <= n; ++i) a[i] = a[i - 1] + w[i];
	sort(a + 1, a + n + 1);
	cout << a[n / 2 + 1];
	return 0;
}