# coding: utf-8

def comp_digit(a:str, b:str):
    assert len(a) == 1
    assert len(b) == 1
    if a == b:
        return "="
    if a == "4" and b == "7":
        return ">"
    if a == "7" and b == "4":
        return "<"
    if a < b:
        return "<"
    return ">"


def larger(a:int, b:int):
    sa = str(a)
    sb = str(b)
    if len(sa) > len(sb):
        return a
    if len(sa) < len(sb):
        return b
    for i in range(len(sa)):
        c = comp_digit(sa[i], sb[i])
        if c == ">": return a
        if c == "<": return b


A, B = map(int, input().split())
print(larger(A, B))