#include <stdio.h>
#include <stdlib.h>

inline unsigned long long int nrdiv(unsigned long long int n,unsigned long long int k)
{
    unsigned long long int s=0;
    while(n>0){
        s+=n/k;
        n=n/k;
    }
    return s;
}

int main()
{
    unsigned long long int n;
    FILE*fi,*fo;
    fi=fopen("gfact.in","r");
    fo=fopen("gfact.out","w");
    fscanf(fi,"%llu",&n);
    unsigned long long int s=0;
    while(nrdiv(s,n)<1)
        s++;
    fprintf(fo,"%llu",s);
    fclose(fi);
    fclose(fo);
    return 0;
}