#include <iostream>
#include <fstream>
using namespace std;

int nrcif(int n)
{
    int cop=n,k=0;

    while(cop==0)
    {
        k++;
        cop=cop/10;
    }

    return k;
}

int main()
{
ifstream f("fact.in");
ofstream g("fact.out");
int p,ult=1;
f>>p;
int ok=1,q=0;
while(ok)
{
    q++;
    ult=ult*q;
    if(nrcif(ult)==p+1)
    {
        g<<q;
        ok=0;
    }
}

    return 0;
}