fn main() {
  let a: i32 = input();
  let b: i32 = input();
  let s: String = input();

  let y: f64 = s[3..].parse().unwrap();
  let x = (a + 48) * 60 + b;
  let x = x + ((y * 60.0 + 1e-8) as i32) - 9 * 60;

  println!("{:02}:{:02}", x / 60 % 24, x % 60);
}

fn input<T: std::str::FromStr>() -> T {
  use std::io::Read;
  let stdin = std::io::stdin();
  let stdin = stdin.bytes();
  let token = stdin
    .skip_while(|x| (*x.as_ref().unwrap() as char).is_whitespace())
    .take_while(|x| !(*x.as_ref().unwrap() as char).is_whitespace())
    .map(|x| x.unwrap())
    .collect();
  let token = String::from_utf8(token).unwrap();
  match token.parse() {
    Ok(x) => x,
    Err(_) => panic!("{}", token),
  }
}