import sys

def solve():
    t = input()
    m = (timetomin(t) + 5) % (24 * 60)
    ans = mintotime(m)
    print(ans)

def timetomin(t):
    h, m = map(int, t.split(':'))
    return (h * 60 + m)

def mintotime(m):
    res = '{:02d}:{:02d}'.format(m // 60, m % 60)
    return res

if __name__ == '__main__':
    solve()