#![allow(non_snake_case)]

#[allow(unused_macros)]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut tokens = $s.split_whitespace();
        input_inner! { tokens, $($r)* }
    };

    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut res = String::new();
            ::std::io::stdin().read_to_string(&mut res).unwrap();
            res
        };
        let mut tokens = s.split_whitespace();
        input_inner! { tokens, $($r)* }
    };
}

#[allow(unused_macros)]
macro_rules! input_inner {
    ($tokens:expr)  => {};
    ($tokens:expr,) => {};

    ($tokens:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($tokens, $t);
        input_inner! { $tokens $($r)* }
    };
}

#[allow(unused_macros)]
macro_rules! read_value {
    ($tokens:expr, ( $($t:tt),* )) => {
        ( $(read_value!($tokens, $t)),* )
    };

    ($tokens:expr, [ $t:tt; $len:expr ]) => {
        (0..$len).map(|_| read_value!($tokens, $t)).collect::<Vec<_>>()
    };

    ($tokens:expr, chars) => {
        read_value!($tokens, String).chars().collect::<Vec<_>>()
    };

    ($tokens:expr, usize1) => {
        read_value!($tokens, usize) - 1
    };

    ($tokens:expr, $t:ty) => {
        $tokens.next().unwrap().parse::<$t>().expect("parse error")
    };
}

use std::iter::{ FromIterator };

fn modulo(lhs: i64, rhs: i64) -> i64 {
    assert!(rhs > 0);
    let r = lhs % rhs;
    if r >= 0 { r } else { r + rhs }
}

fn main() {
    input! {
        A: i64,
        B: i64,
        S: chars,
    }

    assert_eq!(S[..3].iter().collect::<String>(), "UTC");
    let sign = match S[3] {
        '+' =>  1,
        '-' => -1,
        _   => panic!(),
    };
    let s_diff = String::from_iter(S[4..].iter());
    let mut it = s_diff.split('.');
    let x: i64 = it.next().unwrap().parse().unwrap();
    let y: i64 = match it.next() {
        Some(s) => s.parse().unwrap(),
        None    => 0,
    };

    let now  = 60*A + B - 9*60;    // UTC, 分単位
    let diff = sign * 60*x + 6*y;  // 分単位

    let ans = modulo(now+diff, 24*60);
    let ans_h = ans / 60;
    let ans_m = ans % 60;
    println!("{:02}:{:02}", ans_h, ans_m);
}