class Solution {

public int findComplement(int num) {

return getDecimalVal(flip(getBinaryVal(num)));

}

public String getBinaryVal(int n) {

StringBuilder sb = new StringBuilder();

while (n > 0) {

sb.append(String.valueOf(n%2));

n /= 2;

}

return sb.reverse().toString();

}

public String flip(String s) {

StringBuilder sb = new StringBuilder();

for (int i=0;i<s.length();i++) {

if (s.charAt(i) == '1') {

sb.append("0");

}

else {

sb.append("1");

}

}

return sb.reverse().toString();

}

public int getDecimalVal(String s) {

int n = 0;

for (int i=0;i<s.length();i++) {

int mul = (int)Math.pow(2, i);

int num = Integer.parseInt(String.valueOf(s.charAt(i)));

n += mul*num;

}

return n;

}

}