#include<iostream>
#include<fstream>
using namespace std;
int main()
{
    long p,s;    
    int y,nr,n;
    ifstream f("fact.in");
    ofstream g("fact.out");
    f>>p;
    s=1;
    nr=0; n=1;
    if(p==0) g<<1;
    else {
    while(nr<=p-1)
    {
        y=n;        
        while(y%5==0 && nr<=p-1) 
        {
                   nr++;
                   y=y/5;
                   }  
        if(n%5==0) n=n+5;                        
        else n++; 
}
g<<n-1; 
}
return 0;
}