add_only_num.py

import sys


def isNumber(s):
    for i in range(len(s)):
    ┆   if s[i] == '-':
    ┆   ┆   try:
    ┆   ┆   ┆   if not s[i+1].isdigit():
    ┆   ┆   ┆   ┆   return False
    ┆   ┆   except Exception:
    ┆   ┆   ┆   return False
    ┆   if ord(s[i]) >= 48 and ord(s[i]) <= 57:
    ┆   ┆   return True

    return False


sum = 0

# It reads three input lines from stdin
# and finds cumulative abs sum of only numbers
for i in range(3):
    line = sys.stdin.readline()
    x = isNumber(line.strip())
    print x
    if x:
    ┆   sum += abs(int(line.strip()))

print(sum)