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:
x=list(input().split())
A=int(x[0])
B=int(x[1])
k=(A+B)/2
if int(k)==k:
     print("%.0f"%k)
else:
     print("IMPOSSIBE")

Submission status: Wrong Answer

Solution code:
x=list(input().split())
A=int(x[0])
B=int(x[1])
if A>B:
     k=(A-B)/2
else:
     k=(B-A)/2
if int(k)==k:
     print("%.0f"%k)
else:
     print("IMPOSSIBE")

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:
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)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

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

# A**2 - 2AK + K**2 = B**2 - 2BK + K**2
# 2(B - A)K = B**2 - A**2
# K = (A + B) / 2

K = (A + B) / 2

#下記で整数かどうかを判定
if K % 1 == 0:
    print(K)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

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

if k%1==0:
  print(k)

else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

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

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

if abs(ab[0] - k) == (abs(ab[1] - k)):
    print(int(k))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
K = (A + B)/2
if K == int(K):
  print(K)
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())
ans = a+b

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

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

Solution code:
A,B = list(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:
  n = (a + b) / 2
else:
  n = 'IMPOSSIBLE'
print(n)

Submission status: Wrong Answer

Solution code:
A, B = map(int, input().split())
if A >= 0 and A != B and B <= 10**9:
    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(' ')]

0<=A
B<=10**9

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(' ')]

0<=A
B<=10**9

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

Submission status: Wrong Answer

Solution code:
num = [int(e) for e in input().split()]

a = num[0]
b = num[1]

K =(a+b)/2

if (abs(a-b))%2 != 0:
    print("IMPOSSIBLE")
else:
    print(K)

Submission status: Wrong Answer

Solution code:
num = [int(e) for e in input().split()]

a = num[0]
b = num[1]

K =(a+b)/2

if (a-b)%2 != 0:
    print("IMPOSSIBLE")
else:
    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+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:
  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=[int(x) for x in input().split()]

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

Submission status: Wrong Answer

Solution code:
def main():
    a, b = [int(x) for x in input().split()]
    if (a+b)%2 == 0:
        k = (a+b)/2
        if (a<k and k<b) or (b<k and k<a):
            print(k)
    else:
        print('IMPOSSIBLE')


if __name__ == '__main__':
    main()

Submission status: Wrong Answer

Solution code:
def main():
    a, b = [int(x) for x in input().split()]
    if (a+b)%2 == 0:
        print((a+b)/2)
    else:
        print('IMPOSSIBLE')


if __name__ == '__main__':
    main()

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

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

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 = (int(x) for x in input().split())

if a > 0 and b > 0:
  print(int((a + b) / 2))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

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

if a > 0:
  print(int( (a + b) / 2 ))
elif a == 0 or b == 0:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = list(map(int,input().strip().split()))
c = (A - B) / 2
d = (B - A) / 2
e = int(0)
if c >=0:
    e = A - c
else:
    e = B - d
if e % 1 == 0:
    print(e)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = list(map(int,input().strip().split()))
c = (A - B) / 2
d = (B - A) / 2
if c >=0:
    e = A - c
else:
    e = B - d
if e % 1 == 0:
    print(e)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
print(a-549034394,b-549034394)

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 'IMPOSSIBLE')

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

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

if (B%2!=A%2):
  print("IMPOSSIBLE")
  
else:
  print((B-A)//2)

Submission status: Wrong Answer

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

if B%2!=A%2:
  print("IMPOSSIBLE")
  
else:
  print((B-A)//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().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=(a+b)/2
if c%1==0:
    print(c)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
ab = a + b
if ab % 2 == 0:
    print(ab//2)
else:
    print('IMPOSSIBLE2')

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('IMPOSSIBLE')
else:
  h=(a+b)/2
  print(h)

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

Submission status: Wrong Answer

Solution code:
import math
A,B = map(int, input().split())
K = A+B/2
print(K)
if K.is_integer():
    print(math.floor(K))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import math
A,B = map(float, input().split())
K = A+B/2
if K.is_integer():
    print(math.floor(K))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import math
A,B = map(float, input().split())
K = (A**2-B**2)/(2*(A-B))
if K.is_integer():
    print(math.floor(0-K))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
import math
A,B = map(float, input().split())
K = (A**2-B**2)/(2*(A-B))
if K.is_integer():
    print(math.floor(K))
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A,B = map(float, input().split())
K = (A**2-B**2)/(2*(A-B))
if K.is_integer():
    print(K)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

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())

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

Submission status: Wrong Answer

Solution code:
a,b = map(int, input().split())
sa = max(a,b)-min(a,b)
if sa % 2 != 0:
  print("IMPOSSIBLE")
  print(0000)
else:
  print(min(a,b) + sa%2)

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

Solution code:
#135  Harmony
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())
if A == 0 or B == 0:
    K = 'IMPOSSIBLE'
elif A != B:
    K = int(abs(A+B)/2)
else:
    K = 0
print(K)

Submission status: Wrong Answer

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

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 == 1:
  print("IMPOSSIBLE")
else:
  print((a+b)/2)

Submission status: Wrong Answer

Solution code:
import math
a,b=map(int,input().split())
k=abs((a-b)/2)  
k1=math.trunc(k)
if (k-k1)==0 and k!=0:
    print(int(k))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
import math
a,b=map(int,input().split())
k=abs((a-b)/2)
k1=math.trunc(k)
if (k-k1)==0:
    print(int(k))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
import math
a,b=map(int,input().split())
k=abs((a-b)/2)
k1=math.trunc(k)
if (k-k1)>0:
    print('IMPOSSIBLE')
else:
    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 = (int(x) for x in input().split())
if (a - b) % 2 == 0:
    print(int((a + b) / 2))
else:
    print("INPOSSIBLE")

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())
print((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:
    K = (A+B)/2
    print(K)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

Solution code:
A, B = list(map(int, input().split()))
C = max(A, B)
for i in range(C):
  if abs(A-i) == abs(B-i):
    print(i)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
A, B = list(map(int, input().split()))
C = min(A, B)
for i in range(C):
  if abs(A-i) == abs(B-i):
    print(i)
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:
n=[int(i) for i in input().split()]
ans=n[0]+n[1]
if(ans%2==0):
  print(ans)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

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

# print(ans)

Submission status: Wrong Answer

Solution code:
A,B = map(int,input().split())
if (A+B) % 2 == 0:
    K = int((A+B)/2)
    print(K)
elif (A+B) % 2 == 1:
    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)=="float"):
    print("IMPOSSIBLE")
elif(type(k)=="int"):
    print(k)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
k = (a*a - b*b)/(2*a-2*b)

if float.is_integer(k):
    print(k)
else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
k = (a*a - b*b)/(2*a-2*b)

try:
    print(int(k))
except:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
k = (a**2 + b**2)/(2*a-2*b)

if isinstance(k, float):
    print("IMPOSSIBLE")
else:
    print(k)

Submission status: Wrong Answer

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

if K:
  print(K)
else:
  print('IMPOSSIBLE')

Submission status: Wrong Answer

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

A = temp[0]
B = temp[1]

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

Submission status: Wrong Answer

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

k=0
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=int(a+b)
if k%2==0:
  print(str(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(str(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/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) / 2
if (A + B) % 2 == 0:    
    if A - k > 0 and B - k < 0:
        print('pat1')
        print(int(k))
    elif A - k < 0 and B - k > 0:
        print('pat2')
        print(int(k))    
    else:
        print('IMPOSSIBLE')
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
AB = input().split()
A = int(AB[0])
B = int(AB[1])

if A + B % 2 == 1:
    print("IMPOSSIBLE")
else:
    print(int( (A+B)/2 ) )

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

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())

x = (a + b)/2

if  (a + b)%2 == 0 and abs(a - x) == abs(b - x):
    print(x)

else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:

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

x = (a + b)/2

if a != b and abs(a - x) == abs(b - x):
    print(x)

else:
    print("IMPOSSIBLE")

Submission status: Wrong Answer

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

Submission status: Wrong Answer

Solution code:
a,b=map(int,input().split())
c=a-b
d=c//2
if c%2==1:
    ans="IMPOSSIBLE"
elif c%2==0:
    if c>=0:
        ans=b+d
    elif c<0:
        ans=2-d
print(ans)

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    ans = 0
    flag = 0

    if (a%2 != b%2):
        flag = 0
    else:
        ans = abs(a-b)/2 + a
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

if flag == 1:
    print(int(ans))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    ans = 0
    flag = 0

    if abs(a-b)%2 != 0:
        flag = 0
    else:
        ans = abs(a-b)/2 + a
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

if flag == 1:
    print(int(ans))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    ans = 0
    flag = 0

    if abs(a-b)%2 != 0:
        flag = 0
        print('aaaa')
    else:
        ans = abs(a-b)/2 + a
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

if flag == 1:
    print(int(ans))
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

Solution code:
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    ans = 0
    flag = 0

    if abs(a-b)%2 != 0:
        flag = 0
        print('aaaa')
    else:
        ans = abs(a-b)/2 + a
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

if flag == 1:
    print(ans)
else:
    print('IMPOSSIBLE')

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

if (A-B)%2==0:
  print(answer)
else :
  print('imposible')

Submission status: Wrong Answer

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

if (A-B)%2==0:
  print(answer)
else :
  print('imposible')

Submission status: Wrong Answer

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

if A-B%2==0:
  print(answer)
else :
  print('imposible')

Submission status: Wrong Answer

Solution code:
inputs = input().split()
a = int(inputs[0])
b = int(inputs[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())
print('IMPOSSIBLE' if A%2 != B%2 else abs(B-A) // 2)

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

Solution code:
# -*- coding:utf8 -*-

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

Submission status: Wrong Answer

Solution code:
# -*- coding:utf8 -*-

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

Submission status: Wrong Answer

Solution code:
# -*- coding:utf8 -*-

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 == 1:
    print("IMPOSSIBLE")
else:
    print(int((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 = list(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())
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 % 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 ==1:
    print("IMPOSSIBLE")
else:
    print(int((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())

if (a+b)%2 == 1:
  print("IMMPOSSIBLE")
else:
  print(int((a+b)/2))

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

if A%2 == 0 and 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('IMPOSSIBLE')
else:
    print((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 = list(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 (a+b)%2 != 0:
  print('IMPOSSIBLE')
else:
  print(c)

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

Submission status: Wrong Answer

Solution code:
A = list(map(int, input().split()))
if (A[0] - A[1]) %2 != 0:
  print('impossible')
  exit()
print( int( abs(A[0]+ (A[1] - A[0])/2 ) ) )

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

t = a + b

if t // 2 == 1:
	print('IMPOSSIBLE')
else:
	print(t // 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+b)%2==0:print((a+b)/2)
else:print("IMPOSSIBLE")

Submission status: Wrong Answer

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

if i[0]%2 != i[1]%2:
    print("IMPOSSIBLE")
else:
    print((abs(i[0] - i[1]))/2)

Submission status: Wrong Answer

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

if i[0]%2 != i[1]%2:
    print("IMPOSSIBLE")
else:
    print((abs(i[0] - i[1]))/2)

Submission status: Wrong Answer

Solution code:
A ,B = map(int,input().split())
mean = (A+B)/2.0
if isinstance(mean, int)==True:
  print(int(mean))
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
A ,B = map(int,input().split())
mean = (A+B)/2.0
if isinstance(mean, int)==True:
  print(int.mean)
else:
  print("IMPOSSIBLE")

Submission status: Wrong Answer

Solution code:
# インプットの入力
A, B = map(int, input().split())

if (abs(A - B) % 2 == 0) :
	X = abs(A - B) % 2 + min([A, B])
else:
	X = "IMPOSSIBLE"

# 出力
print("{0}".format(X))

Submission status: Wrong Answer

Solution code:
# インプットの入力
A, B = map(int, input().split())

if (abs(A - B) % 2 == 0) :
	X = abs(A - B)
else:
	X = "IMPOSSIBLE"

# 出力
print("{0}".format(X))

Submission status: Wrong Answer

Solution code:
# インプットの入力
A, B = map(int, input().split())

if ((A - B) % 2 == 0) :
	X = abs(A - B)
else:
	X = "IMPOSSIBLE"

# 出力
print("{0}".format(X))

Submission status: Wrong Answer

Solution code:
# インプットの入力
A, B = map(int, input().split())

if (A - B % 2 == 0) :
	X = abs(A - B)
else:
	X = "IMPOSSIBLE"

# 出力
print("{0}".format(X))

Submission status: Wrong Answer

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

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

if(abs(a-b)%2==0):  
  print('{:.0f}'.format(abs(b-(abs(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")