q074.rs

fn main() {
    proconio::input! {
        _n: usize,
        s: String,
    }
    let mut cnt: i64 = 0;
    for (i, c) in s.chars().enumerate() {
        match c {
            'c' => {cnt += 2 << i;},
            'b' => {cnt += 1 << i;},
            _ => {},
        }
    }
    println!("{}", cnt);
}