use std::env;
use std::fs;
use std::collections::HashSet;

fn main() {
    let input = fs::read_to_string(&env::args().nth(1).unwrap()).unwrap();

    let mut sum: u64 = 0;
    for line in input.lines() {
        let mut left_chars: HashSet<char> = HashSet::new();

        for (i, c) in line.char_indices() {
            if i < line.len()/2 {
                left_chars.insert(c);
            } else if left_chars.contains(&c) {
                if c >= 'a' && c <= 'z' {
                    sum += (c as u64) - ('a' as u64) + 1;
                } else {
                    sum += (c as u64) - ('A' as u64) + 27;
                }
                break;
            }
        }
    }

    println!("{:?}", sum);
}