import re

strings = [
    "t1E2S3T",
    "t1E2S33"
]

def emne_validator(emne):
    pattern = r"(?=(?:[^a-zA-Z\n]*[a-zA-Z]){4}[^a-zA-Z\n]*\Z)(?=(?:[^\d\n]*\d){3}[^\d\n]*\Z)"
    m = re.match(pattern, emne)
    return m is not None

for txt in strings:
    result = emne_validator(txt)
    if result:
        print(f"Valid input for: {txt}")
    else:
        print(f"Invalid input for: {txt}")