//Factorial
/*Se da un numar intreg P (0<=P<=108). Problema cere gasirea celui mai 
mic numar natural strict pozitiv N pentru care N! are exact P cifre de
0 la sfarsit*/
#include <stdio.h>
int main ()
{long n, p, i, x, s1=0, s2=0, ok=1, min=2000000000;
FILE *fi, *fo;
fi=fopen ("fact.in","r");
fo=fopen ("fact.out","w");
fscanf(fi,"%ld",&p);
for (i=1;ok;i++)
    {
    x=i;
    while(x%2==0) {s1++;x/=2;}
    while(x%5==0) {s2++;x/=5;}
    if (s1<s2) min=s1;
       else min=s2;
    if(min==p) {ok=0;fprintf(fo,"%ld",i);}
    }
fclose(fi);
fclose(fo);
return 0;
}