#!/usr/bin/env python3
import re

lines = (x.strip() for x in open("input.txt"))
total = 0
regexFirst = re.compile(f"^.*?(\\d)")
regexLast = re.compile(f"^.*(\\d)")

for line in lines:
    first = regexFirst.match(line).group(1)
    last = regexLast.match(line).group(1)
    total += int(first + last)

print(total)