#include using namespace std; #ifdef LOCAL #include "settings/debug.cpp" #else #define Debug(...) void(0) #endif #define rep(i, n) for (int i = 0; i < (n); ++i) using ll = long long; using ull = unsigned long long; int main() { string s; cin >> s; vector cnt(13, 0); for (char c : s) cnt[c - 'a']++; int c = 0; rep(i, 13) { if (cnt[i] == 0) c++; } if (c >= 2) { cout << "Impossible" << endl; } else if (c == 1) { rep(i, 13) if (cnt[i] == 0) cout << char('a' + i) << endl; } else { rep(i, 13) cout << char('a' + i) << endl; } return 0; }