import sys for line in sys.stdin.readlines(): line = line.strip() ret = {} m = len(line) min_c = {} for c in line: ret[c] = line.count(c) if ret[c] < m: min_c = {c} m = ret[c] elif ret[c] == m: min_c.add(c) for c in min_c: line = line.replace(c, '') print(line)