#include<iostream>
#include<string>
using namespace std;
int main(){
    int c;
    double ans,n,a,m=1;
    cin>>n;
    for (int i=1; i<=n; i++) {
        m*=10;
    }
    c=m/7;
    a=c;
    ans=a/m;
    cout<<ans<<endl;
}