Simple inequalities with 1 variable

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
Get lines like that:
x < 42
x > 0.2
x < 0.4
x > 0.3

And print final interval:
0.3 < x < 0.4
"""

import sys


def main() -> None:
    lower = float(-2**32)
    upper = float(2**32)
    for line in sys.stdin:
        line = line.rstrip()
        variable, operator, value_str = line.split()

        assert variable == 'x'

        value = float(value_str)
        if operator == '<':
            upper = min(upper, value)
        else:
            assert operator == '>'

            lower = max(lower, value)

    print(f'{lower} < x < {upper}')


if __name__ == '__main__':
    main()