Buggy python submission (verdict: Time Limit Exceeded):
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    ans = 0
    flag = 0
    if a>b:
        big = a
        small = b
    else:
        big = b
        small = a
        
    for i in range(small,big):
        a_ans = abs(big-i)
        b_ans = abs(small-i)
        if a_ans == b_ans:
            ans = i
            flag = 1
            break
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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

Fixed submission:
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 = (a+b)/2
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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

Buggy python submission (verdict: Runtime Error):
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    
    flag = 0
    if a>b:
        big = a
        small = b
    else:
        big = b
        small = a
        
    for i in range(small,big):
        a_ans = abs(big-i)
        b_ans = abs(small-i)
        if a_ans == b_ans:
            ans = i
            flag = 1
            break
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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

Fixed submission:
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 = (a+b)/2
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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

Buggy python submission (verdict: Runtime Error):
a, b = map(int, input().split())
def kansu_return_flag(a,b):
    
    flag = 0
    if a>b:
        big = a
        small = b
    else:
        big = b
        small = a
        
    for i in range(big):
        a_ans = abs(big-i)
        b_ans = abs(small-i)
        if a_ans == b_ans:
            ans = i
            flag = 1
            break
    return flag

flag = kansu_return_flag(a,b)

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

Fixed submission:
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 = (a+b)/2
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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

Buggy python submission (verdict: Runtime Error):
a, b = map(int, input().split())

def kansu_return_flag(a,b):
    
    flag = 0

    for i in range(10**9):
        a_ans = abs(a-i)
        b_ans = abs(b-i)
        if a_ans == b_ans:
            ans = i
            flag = 1
            break
    return flag

flag = kansu_return_flag(a,b)

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

Fixed submission:
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 = (a+b)/2
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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

Buggy python submission (verdict: Time Limit Exceeded):
a, b = map(int, input().split())

for i in range(10**9):
    a_ans = abs(a-i)
    b_ans = abs(b-i)
    if a_ans == b_ans:
        ans = i
        flag = 1
        break

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

Fixed submission:
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 = (a+b)/2
        flag = 1
    return flag,ans

flag,ans = kansu_return_flag(a,b)

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