#include <fstream>

using namespace std;

ifstream f("fact.in");
ofstream g("fact.out");

unsigned pow(unsigned a,unsigned b);

int main()
{

unsigned n,p,i,s=0;
unsigned v[100];

f>>p;

if(p==0) {g<<1; return 0;}

v[1]=1;
i=1;

while(p>v[i])
{
    i++;
    v[i]=v[i-1]*5+1;
}
i--;

while(i&&p)
{
while(p>=v[i])
{ s+=pow(5,i); p-=v[i];}
i--;
}

g<<s;


return 0;
}

unsigned pow(unsigned a,unsigned b)
{
unsigned s=1;
   
while(b)
{
s*=a;
b--;
}

return s;
}