import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

H,M = map(int,read().split(b':'))

t = H * 60 + M + 5
t %= 1440
H,M = divmod(t,60)

print('{:02g}:{:02g}'.format(H,M))