now = gets.split(":").map(&:to_i)

now[1] += 5

if now[0] == 23 && now[1] >= 55
    now[0] = 0
    now[1] = now[1] % 60
elsif now[0] != 23 && now[1] >= 55
    now[0] += 1
    now[1] = now[1] % 60
end
    
print format("%02d:", now[0])
print format("%02d\n", now[1])