import java.util.HashMap;
import java.util.Map;

// 要考虑唯一双射
public class L0205 {
    public static void main(String[] args) throws Exception {
        String s = "egg";
        String t = "app";
        System.out.print(isIsomorphic(s, t));
    }

    public static boolean isIsomorphic(String s, String t) {

        Map replace_chart = new HashMap();
        Map replace_chars = new HashMap();

        int length = s.length();
        int i;
        for (i = 0; i < length; i++) {
            if (replace_chart.get(t.charAt(i)) == null) {
                replace_chart.put(t.charAt(i), s.charAt(i));
            } else if (!replace_chart.get(t.charAt(i)).equals(s.charAt(i))){
                return false;
            }
            if (replace_chars.get(s.charAt(i)) == null) {
                replace_chars.put(s.charAt(i), t.charAt(i));
            } else if (!replace_chars.get(s.charAt(i)).equals(t.charAt(i))){
                return false;
            }
        }

        return true;
    }
}