Polycarp is going to participate in the contest. It starts at $h_1:m_1$ and ends at $h_2:m_2$. It is guaranteed that the contest lasts an even number of minutes (i.e. $m_1 \% 2 = m_2 \% 2$, where $x \% y$ is $x$ modulo $y$). It is also guaranteed that the entire contest is held during a single day. And finally it is guaranteed that the contest lasts at least two minutes.

Polycarp wants to know the time of the midpoint of the contest. For example, if the contest lasts from $10:00$ to $11:00$ then the answer is $10:30$, if the contest lasts from $11:10$ to $11:12$ then the answer is $11:11$.


-----Input-----

The first line of the input contains two integers $h_1$ and $m_1$ in the format hh:mm.

The second line of the input contains two integers $h_2$ and $m_2$ in the same format (hh:mm).

It is guaranteed that $0 \le h_1, h_2 \le 23$ and $0 \le m_1, m_2 \le 59$.

It is guaranteed that the contest lasts an even number of minutes (i.e. $m_1 \% 2 = m_2 \% 2$, where $x \% y$ is $x$ modulo $y$). It is also guaranteed that the entire contest is held during a single day. And finally it is guaranteed that the contest lasts at least two minutes.


-----Output-----

Print two integers $h_3$ and $m_3$ ($0 \le h_3 \le 23, 0 \le m_3 \le 59$) corresponding to the midpoint of the contest in the format hh:mm. Print each number as exactly two digits (prepend a number with leading zero if needed), separate them with ':'.


-----Examples-----
Input
10:00
11:00

Output
10:30

Input
11:10
11:12

Output
11:11

Input
01:02
03:02

Output
02:02

Difficulty: introductory

Starter code:

Solutions:
h1, m1 = list(map(int, input().split(':')))
h2, m2 = list(map(int, input().split(':')))
z = h1 * 60 + m1 + h2 * 60 + m2
z //= 2
print(str(z // 60 // 10) + str(z // 60 % 10) + ':' + str(z % 60 // 10) + str(z % 60 % 10))

h1, m1 = list(map(int, input().split(':')))
h2, m2 = list(map(int, input().split(':')))

t1 = h1 * 60 + m1
t2 = h2 * 60 + m2
mid = (t1 + t2) // 2
print(f'{mid // 60:02}:{mid % 60:02}')


a, b = list(map(int, input().split(':')))
c, d = list(map(int, input().split(':')))
x = a * 60 + b
y = c * 60 + d
z = (x + y) // 2
print('%02d:%02d' % (z // 60, z % 60))


s = input()
s1 = input()

h = int(s[:2])
m = int(s[3:])
t = h * 60 + m
h = int(s1[:2])
m = int(s1[3:])
t2 = h * 60 + m

t = (t2 + t) // 2
h = t // 60
m = t % 60
print(h // 10, h %10, ':', m // 10, m % 10, sep = "")


h1, m1 = list(map(int, input().split(':')))
h2, m2 = list(map(int, input().split(':')))

t1 = h1 * 60 + m1
t2 = h2 * 60 + m2

delta = (t2 - t1) // 2
t1_f = t1 + delta
h1_f = t1_f // 60
m1_f = t1_f % 60
print('{:02d}:{:02d}'.format(h1_f, m1_f))


s = input().split(':')
s1 = input().split(':')
ch1 = int(s[0])
m1 = int(s[1])
ch2 = int(s1[0])
m2 = int(s1[1])
vr1 = ch1 * 60 + m1
vr2 = ch2 * 60 + m2
rz = vr2 - vr1
rz //= 2
ch1 = ch1 * 60 + m1 + rz
chas = ch1 // 60
mn = ch1 - chas * 60
if chas < 10:
	s = '0'
	s += str(chas)
	chas = s
if mn < 10:
	s = '0'
	s += str(mn)
	mn = s
print(chas, mn, sep = ":")


h1, m1 = map(int, input().split(":"))
h2, m2 = map(int, input().split(":"))

t1 = h1 * 60 + m1
t2 = h2 * 60 + m2

diff = t2 - t1

t = t1 + diff//2

h3 = t//60
m3 = t%60

print("{:02}:{:02}".format(h3,m3))

h1, m1 = list(map(int, input().split(':')))
h2, m2 = list(map(int, input().split(':')))
q1 = h1*60+m1
q2 = h2*60+m2
q3 = (q1+q2)/2
h3 = int(q3 // 60)
m3 = int(q3 % 60)
print("{:02d}:{:02d}".format(h3,m3))


a, b = map(int, input().split(':'))
c, d = map(int, input().split(':'))
s = a * 60 + b
f = c * 60 + d
ans = s + ((f - s) // 2)
ansh = str(ans // 60)
ansm = str(ans % 60)
print('0' * (2 - len(ansh)) + ansh, '0' * (2 - len(ansm)) + ansm, sep=':')

h1, m1 = list(map(int,input().split(":")))
h2, m2 = list(map(int,input().split(":")))
num = h1 * 60 + m1 + h2 * 60 + m2
num //= 2
num2 = str(num // 60)
num3 = str(num % 60)
if len(num2) == 1:
    num2 = "0"+ num2
if len(num3) == 1:
    num3 = "0"+ num3
print(num2+ ":" + num3)


f = list(map(int, input().split(':')))
s = list(map(int, input().split(':')))

a = f[0]*60 + f[1]
b = s[0]*60 + s[1]

n = (a+b)//2

print('%02d:%02d' %(n//60, n%60)) 



def mp():
    return map(int, input().split(':'))

h1, m1 = mp()
h2, m2 = mp()
r = h1 * 60 + m1 + h2 * 60 + m2
r = r // 2
h3 = str(r // 60)
if len(h3) == 1:
    h3 = '0' + h3
m3 = str(r % 60)
if len(m3) == 1:
    m3 = '0' + m3
print(h3, ':', m3, sep = '')

h1, m1 = list(map(int, input().split(':')))
h2, m2 = list(map(int, input().split(':')))

total1 = h1 * 60 + m1
total2 = h2 * 60 + m2

moy = (total1 + total2) // 2

h3 = moy // 60
m3 = moy % 60

if h3 < 10:
    h3 = '0' + str(h3)
if m3 < 10:
    m3 = '0' + str(m3)

print('{}:{}'.format(h3, m3))


def p(a):
    k = str(a)
    if (a // 10) == 0:
        k = '0' + k
    return k

def main():
    h, m = map(int, input().split(':'))
    h1, m1 = map(int, input().split(':'))
    k = (h * 60 + m + h1 * 60 + m1) // 2
    print(p(k // 60), p(k % 60), sep=':')
 
 
main()


h1, m1 = tuple(map(int, input().split(':')))
h2, m2 = tuple(map(int, input().split(':')))


sered = ((h2 * 60 + m2) - (h1 * 60 + m1)) // 2 + (h1 * 60 + m1)

h = str(sered // 60)
m = str(sered % 60)

if len(h) == 1:
    h = '0' + h
if len(m) == 1:
    m = '0' + m
print(h, m, sep=':')



t1 = [int(i) for i in input().split(':')]

A1 = 60*t1[0]+t1[1]

t2 = [int(i) for i in input().split(':')]

A2 = 60*t2[0]+t2[1]

M = (A1+A2)//2

H = M//60

M = M-(H)*60

print(str(H).zfill(2)+':'+str(M).zfill(2))



a,b=map(int,input().split(':'))
c,d=map(int,input().split(':'))
m=(a*60+b+c*60+d)//2
print(('0'+str(m//60))[-2:],('0'+str(m%60))[-2:],sep=':')


a = input()
b = input()

h1 = int(a[0:2])
m1 = int(a[3:])
h2 = int(b[0:2])
m2 = int(b[3:])

h1 = h1*60 + m1
h2 = h2*60 + m2

h = (h1 + h2) // 2

h1 = h//60
m1 = h - h1*60

print("0"*(2-len(str(h1)))+str(h1)+":"+"0"*(2-len(str(m1)))+str(m1))


h1, m1 = list(map(int, input().split(':')))
h2, m2 = list(map(int, input().split(':')))

minutes = h2 * 60 - h1 * 60 + m2 - m1
minutes //= 2

h1 = h1 + (m1 + minutes) // 60
m1 = (m1 + minutes) % 60

h1 = str(h1)
h1 = '0' * (2 - len(h1)) + h1

m1 = str(m1)
m1 = '0' * (2 - len(m1)) + m1
print(h1 + ':' + m1)


'''input
01:02
03:02
'''
import sys
from collections import defaultdict as dd
from itertools import  permutations as pp
from itertools import combinations as cc
from collections import Counter as ccd
from random import randint as rd
from bisect import bisect_left as bl
import heapq
mod=10**9+7

def ri(flag=0):
	if flag==0:
		return [int(i) for i in sys.stdin.readline().split()]
	else:
		return int(sys.stdin.readline())


h1,m1=[int(i) for i in input().split(":")]
h2,m2=[int(i) for i in input().split(":")]

k1=h1
k2=m1
c=0
while h1!=h2 or m1!=m2:
	m1+=1
	if m1==60:
		h1+=1
		m1=0
	c+=1
c=c//2
while c:
	k2+=1
	if k2==60:
		k1+=1
		k2=0
	c-=1
print("%02d:%02d"%(k1,k2))

def main():
    h1,m1 = list(map(int,input().split(':')))
    h2,m2 = list(map(int,input().split(':')))
    min1 = h1*60+m1
    min2 = h2*60+m2

    diff = min2-min1
    mid = min1+(int(diff/2))
    hr = mid//60
    m = mid%60

    if hr < 10:
        hr = '0'+str(hr)

    if m < 10:
        m = '0'+str(m)

    print(str(hr)+':'+str(m))

main()


s1=input()
s2=input()
h1,h2,m1,m2=int(s1[:2]),int(s2[:2]),int(s1[3:]),int(s2[3:])
v1=h1*60+m1
v2=h2*60+m2
s=(v1+v2)//2
print("0"*(2-len(str(s//60)))+str(s//60)+":"+"0"*(2-len(str(s%60)))+str(s%60))


a = input().split(":")
b = input().split(":")
m = int(a[0]) * 60 + int(a[1]) + int(b[0]) * 60 + int(b[1])
m //= 2
ans = str(m % 60)
if (len(ans) == 1):
	ans = "0" + ans
ans = ":" + ans
ans = str(m // 60) + ans
if len(ans) == 4:
	ans = "0" + ans
print(ans)

a, b = input().split(':'), input().split(':')
a = int(a[0]) * 60 + int(a[1])
b = int(b[0]) * 60 + int(b[1])
t = (a + b) // 2
print(str(t // 60).rjust(2, '0') + ':' + str(t % 60).rjust(2, '0'))

h1, m1 = map(int, input().split(':'))
h2, m2 = map(int, input().split(':'))
diff = h1*60 + m1 + ((h2*60 + m2) - (h1*60 + m1))//2
hres = diff // 60
mres = diff % 60
print(str(hres).zfill(2), str(mres).zfill(2), sep=':')