#include <iostream>  
#include <vector>  
#include <algorithm>  
using namespace std;  
int main() {  
    int m, n;  
    cin >> m >> n;  
    vector<int> john(n);  
    for (int i = 0; i < n; ++i)
        cin >> john[i];  
    sort(john.begin(), john.end());  
    int cnt = 0; 
    int max = john.back();  
    for (int i = 0; i < n; ++i) {  
        int maxOp = (i + 1) * m;  
        if (max > maxOp) 
        cnt++;

        max = john[n - i - 1];  
    }  
    cout << cnt << endl;  
}