#include<iostream>

using namespace std;

int main(const int argc,const char* argv[]){
    int input = atoi(argv[1]);
    int max = 1;
    int count = 0;
    for(int i=0;i<input;i++){
        max *= 10;
    }
    for(int i=0;i<max;i++){
        if(i%7==0)count++;
    }
    cout << count << endl;
    return 0;
}