#include <iostream>
using namespace std;
int main()
{
int x , y;
cin >> x >> y;
int a = 0, b = 0, c , p , n;
n = x, c = x % 10, p =1;
while(n)
{
if(n % 2 == c % 2)
a = a + n % 10 * p, p *= 10;
n /= 10;
}
n = y, c = y % 10, p =1;
while(n)
{
if(n % 2 == c % 2)
b = b + n % 10 * p, p *= 10;
n /= 10;
}
if(a > b)
cout << x;
else
if(a < b)
cout << y;
else
if(x > y)
cout << x;
else
cout << y;
return 0;
}
