#[macro_export]
macro_rules! setup {
    { mut $input:ident: SplitWhitespace $(,)? } => {
        use std::io::Read;
        let mut buf = String::new();
        std::io::stdin().read_to_string(&mut buf).ok();
        let mut $input = buf.split_whitespace();
    };
}

#[macro_export]
macro_rules! parse_next {
    ($str_iter:expr) => {
        $str_iter.next().unwrap().parse().ok().unwrap()
    };
}

fn main() {
    setup! { mut input: SplitWhitespace };

    let a: u64 = parse_next!(input);
    let b: u64 = parse_next!(input);
    let c: u64 = parse_next!(input);

    let ans = (|| {
        let mut left = 0;
        let mut right = c + 1;
        while right - left > 1 {
            let mid = (left + right) / 2;
            match (mid - (mid / a)).saturating_add((mid / a).saturating_mul(b)) >= c {
                true => right = mid,
                false => left = mid,
            }
        }
        right
    })();

    println!("{}", ans);
}