#include <stdio.h>

int main()
{
    char s[14];
    int f = 0;
    scanf("%s",&s);
    for (int i = 0;i < 12;i++) {
        int c = 0;
        for (int j = i + 1;j < 13;j++) {
            if (s[i] == s[j]) c++;
            if (c) {
                f++;
                break;
            }
        }
    }
    if (f != 6) {
        puts("Impossible");
        return 0;
    }
    for (int i = 0;i < 13;i++) {
        for (int j = 0;j < 13;j++) {
            if (i == j)continue;
            if (s[i] == s[j]) break;
            if (j == 12) printf("%c\n",s[i]);
        }
    }
}