fn main() {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).unwrap();
    let s: Vec<u64> = buf.split_whitespace().map(|s| s.parse().unwrap()).collect();
    let mut count = s[2];
    if s[0] <= s[2] {
        count -= 1;
    }
    if s[1] <= s[2] {
        count -= 1;
    }
    println!("{}", count);
}