# -*- coding: utf-8 -*-

from decimal import Decimal, ROUND_HALF_UP, ROUND_HALF_EVEN





nums = list(map(int, input().rstrip().split()))



#----------

average = (nums[0] + nums[1]) / 2

print(( Decimal(str(average)).quantize(Decimal('0'), rounding=ROUND_HALF_UP)))

# -*- coding: utf-8 -*-



a,b = [int(i) for i in input().rstrip().split()]

print(( ((a+b) + (2-1)) // 2 ))

# -*- coding: utf-8 -*-
from decimal import Decimal, ROUND_HALF_UP, ROUND_HALF_EVEN

nums = list(map(int, input().rstrip().split()))
# ----------
average = (nums[0] + nums[1]) / 2
print((Decimal(str(average)).quantize(Decimal("0"), rounding=ROUND_HALF_UP)))

# -*- coding: utf-8 -*-
a, b = [int(i) for i in input().rstrip().split()]
print((((a + b) + (2 - 1)) // 2))

-from decimal import Decimal, ROUND_HALF_UP, ROUND_HALF_EVEN - -nums = list(map(int, input().rstrip().split())) -average = (nums[0] + nums[1]) / 2 -print((Decimal(str(average)).quantize(Decimal("0"), rounding=ROUND_HALF_UP))) +a, b = [int(i) for i in input().rstrip().split()] +print((((a + b) + (2 - 1)) // 2))