#include <stdio.h>

int num_divisor(int n){
    int i=0,count=0,s=0;
    for(i=1;i<=n;i++){
        if(n%i==0){
            s=s+i;
            count++;
        }
    }
    return count;
}
int main(void){
    int N;
    scanf("%d",&N);
    int count = 0;
    int n = 0;
    while(count != N){
       if(num_divisor(++n) == 4) ++count;
    }
    printf("%d\n",n);
    return 0;
}