#include <stdio.h>
FILE *f;
long a[11],i,j,n,s;
int main()
{f=fopen("fact.in","r");fscanf(f,"%ld",&n);fclose(f);
 a[1]=5;a[2]=25;a[3]=125;a[4]=625;a[5]=3125;a[6]=15625;a[7]=78125;
 a[8]=390625;a[9]=1953125;a[10]=9765625;
 while(s<n)
 {i+=5;for(j=1;j<=10;j++)if(i%a[j]!=0)break;j--;
  s+=j;
 }
 if(n==0)i=1;
 f=fopen("fact.out","w");
 if(s==n)fprintf(f,"%ld",i);else fprintf(f,"-1");
 fclose(f);
 return 0;
}