#include <cstdio>
#include <string>
#include <iostream>
using namespace std;
char preh[256], revh[256];
string s1, s2, s3;
int main()
{
	freopen("enc.in", "r", stdin);
	freopen("enc.out", "w", stdout);
	cin >> s1 >> s2 >> s3;
	if (s1.size() != s2.size())
		cout << "ERROR";
	else
	{
		for (string::iterator i1 = s1.begin(), i2 = s2.begin(); i1 != s1.end(); ++i1, ++i2)
		{
			if (preh[*i1] == 0 && revh[*i2] == 0)
				preh[*i1] = *i2,
				revh[*i2] = *i1;
			else if (preh[*i1] == *i2&& revh[*i2] == *i1) continue;
			else { cout << "ERROR"; return 0; }
		}
		for (string::iterator i3 = s3.begin(); i3 != s3.end(); ++i3)
			if (revh[*i3] == 0) { cout << "ERROR"; return 0; }
			else putchar(revh[*i3]);
	}
	return 0;
}