// ---------- begin chmin, chmax ----------
pub trait ChangeMinMax {
    fn chmin(&mut self, x: Self) -> bool;
    fn chmax(&mut self, x: Self) -> bool;
}

impl<T: PartialOrd> ChangeMinMax for T {
    fn chmin(&mut self, x: Self) -> bool {
        *self > x && {
            *self = x;
            true
        }
    }
    fn chmax(&mut self, x: Self) -> bool {
        *self < x && {
            *self = x;
            true
        }
    }
}
// ---------- end chmin, chmax ----------
// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------

fn run() {
    input! {
        c: [usize1; 26],
        k: [usize; 26],
        n: usize,
        e: [(bytes, usize1, usize1, i64); n],
    }
    let inf = std::i64::MAX / 2 - 1;
    const SIZE: usize = 16;
    let mut ans = [0i64; SIZE];
    let mut ok = [true; SIZE];
    for (i, (c, k)) in c.into_iter().zip(k).enumerate() {
        type Mat = [[i64; SIZE]; SIZE];
        let mul = |a: &Mat, b: &Mat| -> Mat {
            let mut c = [[-inf; SIZE]; SIZE];
            for (c, a) in c.iter_mut().zip(a) {
                for (a, b) in a.iter().zip(b) {
                    for (c, b) in c.iter_mut().zip(b) {
                        c.chmax(*a + *b);
                    }
                }
            }
            c
        };
        let mut trans = [[-inf; SIZE]; SIZE];
        for i in 0..SIZE {
            trans[i][i] = 0;
        }
        let mut t = trans;
        let op = b'A' + i as u8;
        for &(ref s, a, b, e) in e.iter() {
            if s.contains(&op) {
                trans[a][b].chmax(e);
                trans[b][a].chmax(e);
            }
        }
        let mut r = trans;
        let mut x = k;
        while x > 0 {
            if x & 1 == 1 {
                t = mul(&t, &r);
            }
            r = mul(&r, &r);
            x >>= 1;
        }
        let p = 10i64.pow(7) * k as i64;
        for (i, (ans, ok)) in ans.iter_mut().zip(ok.iter_mut()).enumerate() {
            let v = t[c][i];
            if v < -p {
                *ok = false;
            } else {
                *ans += v;
            }
        }
    }
    if let Some(v) = ans.iter().zip(ok).filter(|p| p.1).max() {
        println!("{}", v.0);
    } else {
        println!("Impossible");
    }
}

fn main() {
    run();
}