#include <algorithm>
#include <array>
#include <bitset>
#include <complex>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <queue>

using namespace std;

struct BoolName : numpunct<char> {
  string t, f;
  BoolName (string t = "Yes", string f = "No") : t(t), f(f) {}
  string do_truename() const {return t;}
  string do_falsename() const {return f;}
};

struct Initializer {
  Initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout << fixed << setprecision(15) << boolalpha;
    cout.imbue(locale(cout.getloc(), new BoolName));
  }
} initializer;

template<typename T> istream& operator>>(istream &s, vector<T> &v) {
  for (T &t : v) s >> t;
  return s;
}

template<typename T> ostream& operator<<(ostream &s, const vector<T> &v) {
  for (const T &t : v) s << t << endl;
  return s;
}

void set_bool_name(string t, string f) {
  cout.imbue(locale(cout.getloc(), new BoolName(t, f)));
}

template<typename T> class Addition {
public:
  template<typename V> T operator+(const V& v) const {
    return T(static_cast<const T&>(*this)) += v;
  }
};

template<typename T> class Subtraction {
public:
  template<typename V> T operator-(const V& v) const {
    return T(static_cast<const T&>(*this)) -= v;
  }
};

template<typename T> class Multiplication {
public:
  template<typename V> T operator*(const V& v) const {
    return T(static_cast<const T&>(*this)) *= v;
  }
};

template<typename T> class Division {
public:
  template<typename V> T operator/(const V& v) const {
    return T(static_cast<const T&>(*this)) /= v;
  }
};

template<typename T> class Modulus {
public:
  template<typename V> T operator%(const V& v) const {
    return T(static_cast<const T&>(*this)) %= v;
  }
};

template<typename T> class IndivisibleArithmetic : public Addition<T>, public Subtraction<T>, public Multiplication<T> {};

template<typename T> class Arithmetic : public IndivisibleArithmetic<T>, public Division<T> {};

struct Time : public Addition<Time>, public Subtraction<Time> {
  int hour, minute, second;

  Time() : hour(0), minute(0), second(0) {}

  Time(int hour, int minute, int second) : hour(hour), minute(minute), second(second) {normalize();}

  int toMinutes() const {
    return hour * 60 + minute;
  }

  int toSeconds() {
    return toMinutes() * 60 + second;
  }

  void normalize() {
    while (second < 0) {
      --minute;
      second += 60;
    }
    while (second >= 60) {
      ++minute;
      second -= 60;
    }
    while (minute < 0) {
      --hour;
      minute += 60;
    }
    while (minute >= 60) {
      ++hour;
      minute -= 60;
    }
    while (hour < 0) hour += 24;
    while (hour >= 24) hour -= 24;
  }

  Time operator+=(const Time& time) {
    hour += time.hour;
    minute += time.minute;
    second += time.second;
    normalize();
    return *this;
  }

  Time operator-=(const Time& time) {
    hour -= time.hour;
    minute -= time.minute;
    second -= time.second;
    normalize();
    return *this;
  }
};

template<typename T = int64_t> T toInteger(const string&);

template<> int toInteger<int>(const string& s) {
  return stoi(s);
}

template<> int64_t toInteger<int64_t>(const string& s) {
  return stoll(s);
}

template<typename T = int64_t> T toInteger(const string& s, int n) {
  T res = 0;
  for (char c : s) {
    if (isdigit(c)) res = res * n + c - '0';
    else if (isalpha(c)) res = res * n + tolower(c) - 'a' + 10;
  }
  return s[0] == '-' ? -res : res;
}

int main() {
  string t;
  cin >> t;
  int h = toInteger(t.substr(0, 2));
  int m = toInteger(t.substr(3, 2));
  Time time(h, m, 0);
  time += Time(0, 5, 0);
  cout << setw(2) << setfill('0') << time.hour << ":" << setw(2) << setfill('0') << time.minute << endl;
}