static void Main(string[] args)
{
string s1 = Console.ReadLine();
string s2 = Console.ReadLine();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < s1.Length; i++)
{
if (s1[i] == s2[i])
sb.Append("0");
else
sb.Append("1");
}
Console.WriteLine(sb.ToString());
Console.ReadLine();
}