--replacement-length greater than 51 hangs indefinetly

[kittenswolf]

Steps to repro: pyminifier --obfuscate-variables --obfuscate-functions --replacement-length=52 test.py

test.py:

def test():
    x = "hello world!"
    y = "123"
    z = "987"
    print(z + x + y)
test()

Expected result: The input should be obfuscated. Actual result: pyminifier hangs indefinetly.