include <stdio.h>

include <stdlib.h>

include <math.h>

int main() {

int a,i,j,max;
scanf("%d",&a);
for(i=2;i<sqrt(a);i++){
    if(a%i==0){
        j=a/i;
        break;
    }
}
if(i>j){
    max=i;
}
else{
    max=j;
}
printf("%d",max);
return 0;

}