#include<stdio.h>

long long int p,v[12],seg[12],tot;

int i,t,coef[12];

long long int pet(int a, int b)
 
{long long int i=a; if(b==0)return 1;
b--;
while(b--)a*=i;
return a;
}




int main(void){

freopen("fact.in","r",stdin);
freopen("fact.out","w",stdout);

for(i=0; i<12; i++)v[i]=pet(5,i);

for(i=0; i<12; i++)seg[i]=pet(5,i+1)/4;

scanf("%lld",&p); if(p==0) printf("%d",1); else {


for(i=11; i>-1; i--){coef[i]=p/seg[i]; p-=coef[i]*seg[i];}

for(i=0; i<12; i++)if(coef[i]==5)t=1;


if(t)printf("%d",-1);

else { for(i=0; i<12; i++)tot+=coef[i]*v[i];
        
        printf("%lld",5*tot); } 

}

return 0;
}