Problem:


Score: 100 points

Problem Statement

We have two distinct integers A and B.

Print the integer K such that |A - K| = |B - K|.

If such an integer does not exist, print IMPOSSIBLE instead.

Constraints

All values in input are integers.

0 \leq A,\ B \leq 10^9

A and B are distinct.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the integer K satisfying the condition.

If such an integer does not exist, print IMPOSSIBLE instead.

Sample Input 1

2 16

Sample Output 1

9

|2 - 9| = 7 and |16 - 9| = 7, so 9 satisfies the condition.

Sample Input 2

0 3

Sample Output 2

IMPOSSIBLE

No integer satisfies the condition.

Sample Input 3

998244353 99824435

Sample Output 3

549034394



Sample input:
2 16


Sample output:
9

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
if (A+B)%2 == 0:
  l = A+B
  print(l//2.0)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
if (A+B)%2 == 0:
  l = A+B
  print(l/2.0)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
if (A+B)%2 == 0:
  print((A+B)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
# a,b=map(int,input())
# n=int(input())
# n=input()
a,b=[int(s) for s in input().split()]
ans=(a-b)/2
if ans==int(ans):
    print(int(ans))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
# a,b=map(int,input())
# n=int(input())
# n=input()
a,b=[int(s) for s in input().split()]
ans=(a-b)/2
if ans==int(ans):
    print(ans)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
print ((a+b)/2 if (a-b)%2==0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
print (abs((a-b)/2) if (a-b)%2==0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())
if (a+b) % 2 ==0:
  print((a+b)/2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a + b) % 2 == 0:
  print((a + b) / 2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
C = max(A,B)
for K in range(C-1):
  if abs(A-(K+1)) == abs(B-(K+1)):
    print(K)
    exit()

print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int, input().split())

d=abs(a-b)
if d%2 == 0:
    print(int(d/2))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
ans=abs(a-b)/2
if ans is not int:
  ans="IMPOSSIBLE"
print(ans)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a-b)%2==1:
  print("IMPOSSIBLE")
else:
  print(abs(a-b)/2)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a+b)%2==1:
    print('IMPOSSIBLE')
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
A,B=map(int,input().split())
K = (A+B)/2
if K % 2 == 0:
    print(int(K))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
if (A+B)%2==0:
  print((A+B)/2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = list(map(int, input().split()))
if (a + b) % 2 == 0 :
  print((a + b) / 2)
else :
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a + b) % 2 == 0 :
  print((a + b) / 2)
else :
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
N1, N2 = map(int,input().split())
diff = abs(N1 - N2)
if diff % 2 == 0:
  print(min(N1,N2) + (diff / 2))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
N1, N2 = map(int,input().split())
diff = abs(N1 - N2)
if diff % 2 == 0:
  print(min(N1,N2) + diff / 2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
c = a + b
if c % 2 == 0:
    print(c/2)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a+b % 2 == 0:
    print(int((a+b)/2))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a+b % 2 == 0:
    print((a+b)/2)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
k=(a+b)/2
if k%1==0:
    print(k)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
K = (A+B)/2
if (A == B):
    print("IMPOSSIBLE")
else:
    if (A+B)%2 == 0:
        print(K)
    else:
        print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
K = (A+B)/2
if (A+B)%2 == 0:
    print(K)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
K = (A+B)/2
if (A-B)%2 == 0:
    print(K)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B= map(int, input().split())		#type int
if ((A+B)/2)%2 == 0:
	print(int((A+B)/2))
else:
	print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())

K = (A^2 - B^2)/(2*(A-B))
if type(K) == int:
  print(K)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=list(map(int,input().split()))
if abs(a-b)%2==0:
  print(int(abs(a-b)/2))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if a%2 != b%2:
	print("IMPOSSIBLE")
else:
	k=(a+b)/2
	print(k)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if a%2 != b%2:
	print('IMPOSSIBLE')
else:
	k=(a+b)/2
	print(k)

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())

if (A + B) % 2 == 0:
    print((A + B) / 2)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

if a % 2 == b % 2:
  print((a + b) / 2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split(" "))
print(int(abs((a-b)/2)) if abs((a-b)/2)%1==0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a + b) % 2 != 0:
    print('IMPOSSIBLE')
else:
    print((a + b)/2)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if a % 2 == 0 and b % 2 == 0: 
    print('IMPOSSIBLE')
else:
    print((a + b)/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int,input().split())
if (a+b)%2:
    print("IMPOSSIBLE")
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a+b)%2==0:
    print((a+b)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a+b%2==0:
    print((a+b)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().strip().split(' '))
if (A+B)%2 == 0:
  print((A+B)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b=map(int, input().split())
if (a+b)%2==0:
    if a+b>0:
        print(int((a+b)/2))
    else:
        print(int((a+b)/-2))
else:
    print('IMPOSIBLE')

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
i = 0
for K in range(A, B):
  if abs(A - K) == abs(B - K):
    print(K," ")
    i = 1
if i == 0:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
ans = (a+b)/2 if (a+b) % 2 == 0 else 'IMPOSSIBLE'
print(ans)

Submission status: Wrong Answer

Solution code:
A,B=map(int,input().split())
if (A+B) % 2 == 0:
  K = (A+B)/2
else:
  K ="IMPOSSIBLE"
print(K)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a+b)%2==0:
  print((a+b)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split(" "))
print((a + b)/2) if (a + b) % 2 == 0 else print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a+b)%2 == 1 :
    print("IMPOSSIBLE")
else :
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a,b = (int(x) for x in input().split())


if (a-b)%2 == 1:
  print("IMPOSSIBLE")

else:
  print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
sum=a+b
if sum%2==0:
  print(sum/2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a = [int(s) for s in input().split()]
p = (a[0] + a[1]) / 2
if p == int(p):
  print(p)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

if ((a - b) / 2 ) % 2 == 0:
    print((a + b) // 2 )
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

if ((a - b) / 2 ) % 2 == 0:
    print((a + b) / 2 )
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

if ((a - b) / 2 ) % 2 == 0:
    print((a - b) / 2 )
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
K = (A**2 - B**2) / (2*(A-B))

if round(K,0) == K:
  print(K)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
l = list(map(int,input().split()))
a = l[0]
b = l[1]
if (a+b)%2 == 0:
  print((a+b)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
l = list(map(int,input().split()))
a = l[0]
b = l[1]
if (a+b)%2 == 0:
  print((a+b)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

buf = a - b

if buf % 2 == 0:
	print(buf // 2)
else:
	print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a=input().split(" ")
A=int(a[0])
B=int(a[1])
answer=(A+B)/2
if (A+B)%2==0 :
    print(answer)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a+b) % 4 ==0:
  print(int((a+b)//4))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if (a+b) % 4 ==0:
  print(int((a+b)/4))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int , input().split())
 
if ( (A + B) % 2 == 0 ):
  K = (A+B)/2
  print(K)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int , input().split())
 
if ( (A + B) % 2 == 0 ):
  print((A + B) / 2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int , input().split())
 
if ( A % 2 == B % 2 ):
  print((A + B) / 2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int , input().split())

if ( (A + B) % 2 == 0 ):
  print((A + B) / 2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int , input().split())

if (A + B % 2 == 0):
  print( A + B / 2 )
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
K = abs((A-B)*0.5)
if K.is_integer() == True:
    print(int(K))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())

if (a+b)%2 == 0:
	print((a+b/2))
else:
	print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())

if (a-b)%2 == 0:
	print((a-b/2))
else:
	print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A , B = map(int,input().split())
if (A + B) % 2 == 0:
         print((A + B)/2)
else:
         print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
# -*- coding: utf-8 -*-

a_b_list = list(map(int,input().split()))
a = a_b_list[0]
b = a_b_list[1]

k = (a + b) / 2
l = (a + b) % 2

if l == 0:
  print(k)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
k = (a + b) / 2
l = (a + b) % 2
if l == 0:
    print(k)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
# -*- coding: utf-8 -*-
a, b = map(int, input().split())
k = (a + b) / 2
l = (a + b) % 2
if l == 0:
    print(k)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B=map(int,input().split())

if (A-B)%2==0:
    print(int((A+B)/2))
else :
    print('IMPSSIBLE')

Submission status: Wrong Answer

Solution code:
n,*x=map(int,open(0).read().split())

soreted_x=sorted(x)
cnt=0
for a,b in zip(x,soreted_x):
  if a != b:
    cnt+=1
print('Yes' if cnt==2 or cnt==0 else 'No')

Submission status: Wrong Answer

Solution code:
a = list(map(int, input().split()))

b = a[0] + a[1]

if b % 2 == 0:
  print(b/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a = list(map(int, input().split()))

re = abs(a[0] - a[1])
yes = 0
for i in range(a[0], a[1]):
  if abs(a[0] - i) == abs(a[1] - i):
    print(i)
    yes = 1
    break

if yes == 0:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a = list(map(int, input().split()))

re = abs(a[0] - a[1])
yes = 0
for i in range(a[0] - a[1]):
  if abs(a[0] - i) == abs(a[1] - i):
    print(i)
    yes = 1
    break

if yes == 0:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b= map(int, input().split())
if (a+b)%2==0:
  print((a+b)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b= map(int, input().split())
if (a+b)%2==0:
  k=(a+b)/2
  print(k)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
x,y = map(int,input().split())
if x%2!=y%2:
  print('IMPOSSIBLE')
else:
  print((x+y)/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a+b) % 2 != 0:
    print('IMPOSSIBLE')
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
K = (a+b) / 2
if isinstance(K, float):
	print('IMPOSSIBLE')
if isinstance(K, int):
	print(K)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
K = (a+b)/2
if isinstance(K, float):
	print('IMPOSSIBLE')
else:
	print(K)

Submission status: Wrong Answer

Solution code:
a,b=map(int, input().split())
if (a+b)%2==0:
  print(str((a+b)/2))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int, input().split())
print(str((a+b)/2))

Submission status: Wrong Answer

Solution code:
inp = input().split()
A = int(inp[0])
B = int(inp[1])
if (A + B) % 2== 0:
    print((A+B)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
inp = input().split()
A = int(inp[0])
B = int(inp[1])
if ((A +B) /2) % 2== 0:
    print((A+B)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int, input().split())
if (a+b)//2 == int((a+b)/2):
  print((a+b)//2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
num=input().split()
A=int(num[0])
B=int(num[1])
if A==B:
    print(0)
elif (A+B)%2==0:
    print((A+B)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import itertools

def getint(): return int(input())
def getints(): return list(map(int, input().split()))

a,b=list(sorted(getints()))


print((b-a)//2 if a%2==b%2 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import itertools

def getint(): return int(input())
def getints(): return list(map(int, input().split()))

a,b=list(sorted(getints()))


print((b-a)//2 if (b-a) % 2 == 0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())
if(a==b or (a+b)%2==0):
    print("POSSIBLE")
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

for i in range(10**5):
  c = abs(a-i)
  d = abs(b-i)
  if c==d:
    print(i)
    exit()
print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

for i in range(10**4):
  c = abs(a-i)
  d = abs(b-i)
  if c==d:
    print(i)
    exit()
print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())
if (a+b)%2 == 0:
  print((a+b)%2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = [int(i) for i in input().split()]
if (a + b) / 2 % 1 == 0:
  print(int(a + b / 2))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split());print((a+b)/2 if (a+b)%2==0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int, input().split())
k=(a+b)/2
if a+b % 2 != 0:
    print('IMPOSSIBLE')
else:
    print(int(k))

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())  # 複数数値入力

if (a+b)%2==0:
    print((a + b) / 2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a + b) % 2 != 0:
    print("IMPOSSIBLE")
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a % 2 != b % 2:
    print("IMPOSSIBLE")
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a % 2 == b % 2:
    print((a+b)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a % 2 == b % 2:
    if a > b:
        print((a-b)/2)
    elif a < b:
        print((b-a)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a > b and ((a - b) % 2) == 0:
    print(round((a + b) / 2))
elif a < b and ((b - a) % 2) == 0:
    print(round((b - a) / 2))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Fri Aug  9 22:36:19 2019

@author: kohei
"""

N = input()

A = int(N.split()[0])
B = int(N.split()[1])

if A==B:
    print('IMPOSSIBLE')

else:
    if (A+B)%2==0:
        print((A+B)/2)
    
    else:
        print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A,B=map(int,input().split())
K=(A+B)/2
if (A+B)%2==0:
    print(K)
else: print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
k=(a+b)/2
if (a+b)%2==0:
    print(k)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
dif = abs(A - B)
print(A + dif//2 if dif%2==0 else 'IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
dif = abs(A - B)
print(dif//2 if dif%2==0 else 'IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
if (max(A, B) - min(A, B)) % 2 == 1:
    print("IMPOSSIBLE")
else:
    print(int((A + B)) / 2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

if (max(a,b) - min(a,b)) % 2 == 1:
  print("IMPOSSIBLE")
else:
  print((a+b)/2)

Submission status: Wrong Answer

Solution code:
a = list(map(int, input().split()))
b = a[0] + a[1]
if b%2 == 0:
  print(b/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b = map(int, input().split())
 
if (a + b) % 2 != 0:
    print("IMPOSSIBLE")
elif b > a :
    print(abs(a-b)//2)
else:
    print(abs(a+b)//2)

Submission status: Wrong Answer

Solution code:
a,b = map(int, input().split())
 
if (a + b) % 2 != 0:
    print("IMPOSSIBLE")
else:
    print(abs(a-b)//2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
k = (a+b)/2
if k%2 == 0:
  print(k)
else:
  ('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
List = list(map(int,input().split()))

A = List[0]
B = List[1]

Flag = False
if (A + B) % 2 == 0:
    K = (A + B)/2
    Flag = True
    
if Flag == True:
    print(K)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
c=a%2
d=b%2
if (c-d)==0:
  print((a+b)/2)
else:
  print("'IMPOSSIBLE'")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
c=a%2
d=b%2
if (c-d)==0:
  print((a+b)/2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
D=A+B
if D %2 > 0:
    print('IMPOSSIBLE')
elif D %2 == 0:
    print((A+B)/2)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
D=A+B
if D %2 != 0:
    print('IMPOSSIBLE')
elif D %2 == 0:
    print((A+B)/2)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
D=A+B
if D %2 != 0:
    print('IMPOSSIBLE')
elif D %2 == 0:
    print(C)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
D=A+B
if D %2 != 0:
    print('IMPOSSIBLE')
if D %2 == 0:
    print(C)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
D=A+B
if A==B:
    print(0)
elif D %2 != 0:
    print('IMPOSSIBLE')
else:
    print(C)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
D=A+B
if D %2 != 0:
    print('IMPOSSIBLE')
else:
    print(C)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
if A+B %2 != 0:
    print('IMPOSSIBLE')
else:
    print(C)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
C=(A+B)/2
if A+B %2 == 1:
    print('IMPOSSIBLE')
else:
    print(C)

Submission status: Wrong Answer

Solution code:
A,B = map(int, input().split())
if A+B %2 == 1:
    print('IMPOSSIBLE')
else:
    print((A+B)/2)

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())

if (a+b) % 2 == 0:
  print((a+b)/2)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
print((A+B)//2)

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
print(abs(A-B)//2)

Submission status: Wrong Answer

Solution code:
a=input().split()

a=[int(n) for n in a]

k=(a[0]+a[1])/2

if a[0]%2!=a[1]%2:
    print('IMPOSSIBLE')
else:
    print(k)

Submission status: Wrong Answer

Solution code:
a=input().split()

k=(int(a[0])+int(a[1]))/2

if (int(a[0])+int(a[1]))%2==0:
    if abs(int(a[0])-k)==abs(int(a[1])-k):
        print(k)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
import math

A, B = map(int, input().split())
K = 0

if A % 2 != B % 2:
  print('IMPOSSIBLE')
else:
  print(A + B / 2)

Submission status: Wrong Answer

Solution code:
A,B=map(int,input().split())

if (A+B)%2==0:
    print((A+B)//2)
else:
    print("INPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if ((a+b)%2) == 1:
    print ('IMPOSSIBLE')
else:
    print ((a+b)/2)

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())

if (a+b)%2 == 0:
    print((a+b)/2)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int,input().split())
K = A + B

if K % 2 == 0:
    print(K/2)

else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
K = A + B

if K % 2 == 0:
    print(K)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())

if A+B % 2 == 0:
    print(A+B)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())

if A+B % 2 == 0:
    print(A+B)
else:
    print("IMPOSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())
if a+b%2 == 1:
  print("IMPOSSIBLE")
else:
  print((a+b)//2)

Submission status: Wrong Answer

Solution code:
a,b = map(int, input().split())

c = (a+b)/2 

if c.is_integer == True:
  print(c)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import sys
input = sys.stdin.readline

a,b = map(int, input().split())

k2 = a+b
k = k2 / 2
if k2 % 2 != 0:
  print("IMPOSSIBLE")
else:
  print(k)

Submission status: Wrong Answer

Solution code:
import sys
input = sys.stdin.readline

a,b = map(int, input().split())

k2 = a+b
if k2 % 2 != 0:
  print("IMPOSSIBLE")
else:
  print(k2/2)

Submission status: Wrong Answer

Solution code:
A,B=(int(x) for x in input().split())
K=(A+B)/2
if abs(A-K) == abs(B-K):
    print(K)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A,B=(int(x) for x in input().split())
A!=B

if (A+B)%2==0:
    print((A+B)%2)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a + b) % 2 == 0:
  print((a+b)/2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
k = sum(list(map(int, input().split())))/2
if k % 1:
    print('IMPOSSIBLE')
    exit()
print(k)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if a-b//2:
    print(abs(a-b)//2+min(a, b))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
"""
- https://atcoder.jp/contests/abc136/tasks/abc135_a
- |A−K|=|B−K| (others:IMPOSSIBLE)
- reg: 0≤A, B≤10^9
"""

a, b = map(int, input().split())
# 三項演算子
k = (a+b) / 2 if (a+b) % 2 == 0 else 'IMPOSSIBLE'

print(k)

Submission status: Wrong Answer

Solution code:
A, B = map(int,input().split())

for i in range(1,10**9):
  if (abs(A-i) == abs(B-i)):
      print(i)
      exit()
  elif abs(abs(A-i)-abs(B-i)) >= abs(A-B):
      break;

print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int,input().split())

num = 0 
for i in range(1,10^9):
  if (abs(A-i) == abs(B-i)):
      print(i)
      exit()

print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
input1 = input()
 
num = input1.split()
 
num1 = int(num[0])
num2 = int(num[1])
 
total = num1 + num2
 
if total%2 != 0:
	print('IMPOSSIBLE')
else:
	print(total/2)

Submission status: Wrong Answer

Solution code:
input1 = input()

num = input1.split(' ')

num1 = int(num[0])
num2 = int(num[1])

total = num1 + num2

if total%2 == 0:
	print('IMPOSSIBLE')
else:
	print(total/2)

Submission status: Wrong Answer

Solution code:
# -*- coding: utf-8 -*-

inputAB = input()
inputAB.split()

inputA = int(inputAB[0])
inputB = int(inputAB[2])

if inputA > inputB:
    largeNum = inputA
    smallNum = inputB
else:
    largeNum = inputB
    smallNum = inputA


if ((largeNum - smallNum) % 2) == 1:
    print("IMPOSSIBLE")
else:
    answer = int( (largeNum - smallNum) / 2)
    print(answer)

Submission status: Wrong Answer

Solution code:
# -*- coding: utf-8 -*-

inputAB = input()
inputAB.split()

inputA = int(inputAB[0])
inputB = int(inputAB[2])

if inputA > inputB:
    largeNum = inputA
    smallNum = inputB
else:
    largeNum = inputB
    smallNum = inputA


if ((largeNum - smallNum) % 2) == 1:
    print("IMPOSSIBLE")
else:
    answer = int(smallNum + (largeNum - smallNum) / 2)
    print(answer)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a+b)%2==0:
    print((a+b)/2)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
if (a + b) % 2 != 0:
    print('IMPOSSIBLE')
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
if A==B:
  K=1
  print(K)
else:
  if (A+B)%2==0:
    K=(A+B)/2
    print(K)
  else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
num = input().split()
a = int(num[0])%2
b = int(num[1])%2
if a!=b: print('IMPOSSIBLE')
else: print((int(num[0])+int(num[1]))/2)

Submission status: Wrong Answer

Solution code:
num = input().split()
a = int(num[0])%2
b = int(num[1])%2
if a!=b: print('IMPOSSIBLE')
else: print((a+b)/2)

Submission status: Wrong Answer

Solution code:
num = input().split()
if int(num[0])+int(num[1])%2!=0:
  print('IMPOSSIBLE')
else:
  print(int(num[0])+int(num[1])//2)

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
if a%2!=b%2:
    print("IMPOSSIBLE")
else:
    print((a+b)/2)

Submission status: Wrong Answer

Solution code:
import sys
a,b=map(int,input().split())
if a%2!=b%2:
    print("IMPOSSIBLE")
    sys.exit()
print((a+b)/2)

Submission status: Wrong Answer

Solution code:
import sys
a,b=map(int,input().split())
if 1==a+b%2:
    print("IMPOSSIBLE")
    sys.exit()
print(int((a+b)/2))

Submission status: Wrong Answer

Solution code:
a,b=list(map(int,input().split()))
c=a+b
if (c)%2 !=0:
    print("IMPOSSIBLE")
else:
    print(c/2)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())

s = (a+b)/2

if abs(a - s) == abs(b - s):
  print(s)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
text = input()
figures = text.split(' ')
a = int(figures[0])
b = int(figures[1])

result = None

if (a - b) % 2 == 0:
	result = int(abs(a - abs((a - b) / 2)))
else:
	result = 'IMPOSSIBLE'
  
print(result)

Submission status: Wrong Answer

Solution code:
def harmony(a,b):
    if (a+b)%2==0:
        return int((a+b)/2)
    else:
        return 'IMPOSSIBLE'

Submission status: Wrong Answer

Solution code:
def harmony(a,b):
    if (a+b)%2==0:
        return int((a+b)/2)
    else:
        return 'IMPOSSIBLE'

Submission status: Wrong Answer

Solution code:
def harmony(a,b):
    if (a+b)%2==0:
        return (a+b)/2
    else:
        return 'IMPOSSIBLE'

Submission status: Wrong Answer

Solution code:
import numpy as np

A,B = map(int,input().split(" "))

if (A-B)%2 == 1:
    print('IMPOSSIBLE')
else:
    print((A+B)/2)

Submission status: Wrong Answer

Solution code:
def main(a, b):
  aa = int(a)
  bb = int(b)
  cc = aa - bb
  if (cc) % 2 == 0:
    return cc
  else:
    return 'IMPOSSIBLE'

if __name__ == '__main__':
  a = input()
  a = a.split(' ')
  main(a[0], a[1])

Submission status: Wrong Answer

Solution code:

def main(a, b):
  if (int(b) - int(a)) % 2 == 0:
    return int(b) - int(a)
  else:
    return 'IMPOSSIBLE'

if __name__ == '__main__':
  a = input()
  a = a.split(' ')
  main(a[0], a[1])

Submission status: Wrong Answer

Solution code:
a, b = map(int, input("").split())
c = (a + b) / 2
print(c if c.is_integer() else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b = map(int,input().split())
if((a + b) % 2 == 1):
    print("IMPOSSIBLE")
else:
    ans = (a + b) / 2
    print(ans)

Submission status: Wrong Answer

Solution code:
inp = input()
a, b = list(map(int, inp.split(" ")))

# |a-k| = |b-k|
# |a-k|^2 = |b-k|^2
# a^2-2ak+k^2 = b^2-2bk+k^2
# 2(b-a)k = (b^2-a^2)
# if b==a or (b+a)%2==1 then k="Impossible" else k=(a+b)/2
if b==a or (a+b)%2==1:
  print("IMPOSSIBLE")
else:
  print(a+b)

Submission status: Wrong Answer

Solution code:
import math
a,b = list(map(int, input().split()))
ab = abs(a-b)
print(int(ab/2)+2 if ab % 2 == 0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import math
a,b = list(map(int, input().split()))
ab = abs(a-b)
print(int((ab+1)/2) if ab % 2 == 0 else "IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())

c=a-b

if c%2==0:
  if a<b:
    print(b-c//2)
  else:
    print(a+c//2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())

a=a-b
if a<0:
  a=-a
if a%2==0:
  print(a//2)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
def function(data):
    data = data.split(" ")
    a = int(data[0])
    b = int(data[1])
    if (a + b) % 2 == 1:
        print("impossible")
    else:
        k = int((a + b) / 2)
        print(k)

if __name__ == '__main__':
  d = input()
  function(d)

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
if (A + B) % 2 == 1:
    print("IMPOSSIBLE")
else:
    print((A + B) / 2)