const MOD: usize = 1e9 as usize + 7;

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 abn = String::new();
    std::io::stdin().read_line(&mut abn).ok();
    let abn: Vec<usize> = abn.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let a = abn[0];
    let b = abn[1];
    let n = abn[2];

    if n == 0 {
        println!("0");
        return
    } else if n == 1 {
        println!("1");
        return;
    }
    let mat = vec![vec![a, b], vec![1, 0]];
    let mat = power_mat(&mat, n-1);
    println!("{}", mat[0][0]);
}