input := fs_read("/tmp/pin.txt").assume_no_enum().bytes_to_string().assume_no_enum()

fn prio(s string) {
    switch! "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".index_of(s) {
        [] [] 0
        int n n + 1
    }
}

sum := 0
for line input.regex(".*").assume_no_enum() {
    left := line.substring(0, line.len() / 2)
    right := line.substring(line.len() / 2)
    for ch right.regex(".").assume_no_enum() {
        if left.contains(ch) {
            &sum = sum + prio(ch)
            true
        }
    }
    []
}

println("sum: " + sum.to_string())