use std::char;

struct State {
    chars: Vec<char>,
    res: String,
}

fn main() {
    let input = "CCGTATAAAGTAAGAAATAAAGTAAGAACTGTAGAGCGATCGTTCGTACCTTCGGCCGCAAGAGATGGAGAAATAAAGTAAGAAAGAGCTAACTAGCGCCCGCAATACAGAGATGGAGAAATAAAGTAAGAAAGAGCTAACTAGCGCCCGCAATAGAGAGATGGAGAAATAAAGTAAGAAAGAGCGCGCTCCCGTGCGATAGAGATGGAGAAATAACTTCAGTAAGAAATAAAGTAAGAAATACCCTC";
    let res: String = input.chars().fold(State {
        chars: vec![],
        res: String::new(),
    }, |state, c| {
        let mut chars = state.chars.clone();
        let mut result = state.res.clone();
        if chars.len() >= 7 {
            let mut res = 0u32;
            for (i, c) in chars.iter().enumerate() {
                let n = match c {
                    'A' => 0,
                    'C' => 1,
                    'G' => 2,
                    _ => 3
                };
                res += n * 4_u32.pow(i as u32);
            }
            println!("{}", res);
            result = format!("{}{}", result, char::from_u32(res).unwrap());
            chars = vec![];
        } else {
            chars.push(c);
        }
        State {
            chars,
            res: result
        }
    }).res;
    println!("{}", res);
}