const MOD: usize = 998244353;

fn power_mat(target: &Vec<Vec<usize>>, times: usize) -> Vec<Vec<usize>> {
    let n = target.len();
    if times == 0 {
        let mut ret = vec![vec![0usize; n]; n];
        for i in 0..n { ret[i][i] = 1; }
        return ret;
    }
    if times == 1 {
        return target.clone();
    }
    let temp = power_mat(target, times/2);
    if times % 2 == 1 {
        calc_mat(&calc_mat(&temp, &temp), target)
    } else {
        calc_mat(&temp, &temp)
    }
}

fn calc_mat(left: &Vec<Vec<usize>>, right: &Vec<Vec<usize>>) -> Vec<Vec<usize>> {
    let sizei = left.len();
    let sizej = right[0].len();
    let sizek = left[0].len();
    let mut ret = vec![vec![0usize; sizej]; sizei];
    for i in 0..sizei {
        for j in 0..sizej {
            ret[i][j] = (0..sizek).map(|k| left[i][k] * right[k][j] % MOD).sum::<usize>() % MOD;
        }
    }
    ret
}

fn main() {
    let mut nmt = String::new();
    std::io::stdin().read_line(&mut nmt).ok();
    let nmt: Vec<usize> = nmt.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nmt[0];
    let m = nmt[1];
    let t = nmt[2];
    let mut op = vec![vec![0usize; n]; n];
    for _ in 0..m {
        let mut temp = String::new();
        std::io::stdin().read_line(&mut temp).ok();
        let temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let u = temp[0];
        let v = temp[1];
        op[u][v] += 1;
        op[v][u] += 1;
    }

    let op = power_mat(&op, t);
    println!("{}", op[0][0]);
}