Codeforces Roma and Lucky Numbers

//#include<cstdio>
//#include<iostream>
//#include<algorithm>
//#include<vector>
//#include<cstring>
//#include<cmath>
//#include<map>
#include<bits/stdc++.h>
using namespace std;

#define fast ios_base::sync_with_stdio(false)
#define bfast cin.tie(0)
#define outs(x) cout << x << " "
#define outn(x) cout << x << "\n"
#define sf scanf
#define pf printf

typedef long long LL;
typedef vector<int>vii;
typedef vector<LL>vll;

int main()
{
    fast;
    int n,k ;
    LL cnt=0, ans=0 , i , len=0;
    string s;
    while(cin >> n >> k)
    {
        cnt=0;
        ans=0;

        while(n--)
        {
            cin >> s;

            len = s.length();

            cnt=0;

            for(i=0; i<len; i++)
            {
                if(s[i] == '4' or s[i] == '7') cnt++;
            }

            if(cnt <= k) ans++;
        }

        outn(ans);
    }

    return 0;
}