Read and analyze a text file

This is a text report there are some lines that start with
Report: 23
Other linese has this somewhere in the middle.

Begin report

Report: -3

Like this. Report: 17
More lines starting with
Report: 44

End report

We will have some exercise with this file. Maybe 4 exercises.
Report: 123

import sys

if len(sys.argv) != 2:
    exit(f"Usage: {sys.argv[0]} FILENAME")

filename = sys.argv[1]

total = 0
with open(filename, "r") as fh:
    for row in fh:
        if "Report" not in row:
        text, value = row.split(":")
        # print(value)
        value = float(value.strip())
        # print(value)
        total += value