const DIVISOR: u64 = 1_000_000_007;

fn power(base: u64, p: u64) -> u64 {
    if p == 0 { return 1u64; }
    if p == 1 { return base; }
    let temp = power(base, p / 2);
    temp * temp % DIVISOR * power(base, p % 2) % DIVISOR
}

fn combs(n: u64, r: u64, nums: &Vec<u64>, dens: &Vec<u64>) -> u64 {
    nums[n as usize] * dens[n as usize - r as usize] % DIVISOR * dens[r as usize] % DIVISOR
}

fn calc_nk(n: u64, k: u64, a: u64, b: u64, inv_n: u64, nums: &Vec<u64>, dens: &Vec<u64>) -> u64 {
    let nk_temp = combs(n, k-1, nums, dens) * inv_n % DIVISOR;
    let nk_val = nk_temp * a % DIVISOR * (n+1-k) % DIVISOR + nk_temp * b % DIVISOR * (k-1) % DIVISOR;
    nk_val % DIVISOR
}

fn main() {
    let mut ab = String::new();
    std::io::stdin().read_line(&mut ab).ok();
    let ab: Vec<u64> = ab.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let a = ab[0] % DIVISOR;
    let b = ab[1] % DIVISOR;
    let mut nk = String::new();
    std::io::stdin().read_line(&mut nk).ok();
    let nk: Vec<u64> = nk.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nk[0];
    let k = nk[1];

    let mut nums: Vec<u64> = vec![1; n as usize + 1];
    let mut dens: Vec<u64> = vec![1; n as usize + 1];
    for i in 1..=(n as usize) {
        nums[i] = nums[i-1] * i as u64;
        nums[i] %= DIVISOR;
        dens[i] = dens[i-1] * power(i as u64, DIVISOR-2);
        dens[i] %= DIVISOR;
    }
    let inv_n: u64 = power(n, DIVISOR-2);
    let mut summary = a * a % DIVISOR + b * b % DIVISOR;
    summary %= DIVISOR;
    for i in 2..=n {
        let temp = calc_nk(n, i, a, b, inv_n, &nums, &dens);
        summary += temp * temp;
        summary %= DIVISOR;
    }
    println!("{}", calc_nk(n, k, a, b, inv_n, &nums, &dens));
    println!("{}", summary);
}