#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

template<typename T> T mod(T x, T y) { return (x % y + y) % y; }
template<typename T> void setmod(T & x, T y) { x = mod(x, y); }

int a, b;
string s;

int main() {
	cin >> a >> b >> s;
	
	a -= 9;
	setmod(a, 24);
	
	if(s.find('.') == -1) { s += ".0"; }
	int v = 0;
	incID(i, 4, s.size()) {
		if(s[i] != '.') {
			v *= 10;
			v += s[i] - '0';
		} else {
			v *= 60;
			v += (s[i + 1] - '0') * 6;
			break;
		}
	}
	if(s[3] == '-') { v *= -1; }
	setmod(v, 24 * 60);
	
	a += (v / 60) + (b + v % 60) / 60;
	b += v % 60;
	setmod(a, 24);
	setmod(b, 60);
	
	printf("%02d:%02d\n", a, b);
	
	return 0;
}