Ugly Number

public class Solution {
    public bool IsUgly(int num) {
        if(num <=) return false;
        if(num==) return true;
        while(num/*==num){
            num = num/;
        }
        while(num/*==num){
            num = num/;
        }
        while(num/*==num){
            num = num/;
        }
        return num==?true:false;
    }
}