import sys

def fun(input_number):
    result_str=''
    input_number= str(input_number)
    for i in range(len(input_number)-1,-1,-1):
        if input_number[i]  not in result_str:
            result_str = result_str + input_number[i]

    return result_str

if __name__ == '__main__':
    input_number=input()
    number = int(fun(input_number))
    print(number)