Rotated Digits

class Solution {
    public int rotatedDigits(int n) {

     int count = 0;
     for(int i=1; i<=n; i++) {
        if(isGood(i))
            count++;
     }
     return count;

    }

    boolean isGood(int num) {
        boolean isValid = false;
        while(num > 0) {
            int rem = num%10;
            if(rem==3 || rem==4 || rem==7)
                return false;
            if(rem==2 || rem==5 || rem==6 || rem==9)
                isValid = true;   
            num = num/10;                    
        }
        return isValid;
    }
}