#include #define rep(i, n) for(int(i) = 0; (i) < (n); (i)++) #define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++) #define ALL(v) (v).begin(), (v).end() #define LLA(v) (v).rbegin(), (v).rend() #define PB push_back #define MP(a, b) make_pair((a), (b)) using namespace std; template inline vector make_vec(size_t a, T val) { return vector(a, val); } template inline auto make_vec(size_t a, Ts... ts) { return vector(a, make_vec(ts...)); } template inline T read() { T t; cin >> t; return t; } template inline vector readv(size_t sz) { vector ret(sz); rep(i, sz) cin >> ret[i]; return ret; } template inline tuple reads() { return {read()...}; } template struct edge { int to; T cost; edge(int t, T c) : to(t), cost(c) {} }; using ll = long long; using pii = pair; using pll = pair; using Graph = vector>; template using WGraph = vector>>; const int INF = 1 << 30; const ll LINF = 1LL << 60; const int MOD = 1e9 + 7; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); string X; cin >> X; sort(LLA(X)); int N = X.size(); int idx = -1; for(int i = N - 2; i >= 0; i--) { if(X[N - 1] != X[i]) { idx = i; break; } } if(idx <= 0) cout << -1 << endl; else { swap(X[idx], X[N - 1]); cout << X << endl; } }