#include <bits/stdc++.h>
using namespace std;


int main() {
    int n;
	cin>>n;
	int k;
	cin>>k;

	vector<int> cost,curr,pre;
	for (int i = 0; i < n; ++i)
	{
		int t;
		cin>>t;
		cost.push_back(t);
		pre.push_back(INT_MAX);
		curr.push_back(0);
	}  
    cout<<n-2;
    return 0;
}