#!/usr/bin/env python3


def solve(x):
    cs = sorted(x, reverse=True)
    n = len(cs)
    for i in range(n - 1)[::-1]:
        if cs[i] > cs[i + 1]:
            cs[i], cs[i + 1] = cs[i + 1], cs[i]
            break
    else:
        return
    y = "".join(cs)
    if y.startswith("0"):
        return
    else:
        return y


def main():
    x = input()
    res = solve(x)
    print(res if res is not None else -1)


if __name__ == "__main__":
    main()