from typing import Dict


def years(full_passports: Dict[str, str], key: str, start: int, end: int) -> bool:
    """
    byr (Birth Year) - four digits; at least 1920 and at most 2002.
    iyr (Issue Year) - four digits; at least 2010 and at most 2020.
    eyr (Expiration Year) - four digits; at least 2020 and at most 2030.
    """

    if full_passports[key].isdigit() and len(full_passports[key]) == 4\
            and int(full_passports[key]) >= start and int(full_passports[key]) <= end:
        return True

    return False