#include<stdio.h>

int main(){
unsigned long P,MAX,OPTIM,p,max,optim;
FILE *fin=fopen("fact.in","r");
FILE *fout=fopen("fact.out","w");
fscanf(fin,"%lu",&P);
p=P+1;

MAX=P*5;
OPTIM=P/5;
if(P%5==0) OPTIM--;
MAX-=OPTIM*5;

max=p*5;
optim=p/5;
if(p%5==0) optim--;
max-=optim*5;

if(MAX==max) fprintf(fout,"%d",-1);

else fprintf(fout,"%lu ",MAX);
fclose(fin);
fclose(fout);
return 0;
}