



"""simple docstring"""


from collections import Counter

def 				_lowerCAmelCase   (     lowercase_		):
						return sum(socks_by_color // 2 for socks_by_color in Counter(lowercase_		).values()		)


if __name__ == "__main__":
				import doctest

				doctest.testmod()

				snake_case_         = [int(x) for x in input("""Enter socks by color :""").rstrip().split()]
				print(f'''sock_merchant({colors}) = {sock_merchant(colors)}''')










"""simple docstring"""


def 				_lowerCAmelCase   (     lowercase_	,			lowercase_		):
						UpperCAmelCase    =				1.0
						for i in range(1	,			r + 1		):
												ret *= (n + 1 - i) / i
						return round(lowercase_		)

def 				_lowerCAmelCase   (     lowercase_		):
						return choose(8 + n	,			lowercase_		) + choose(9 + n	,			lowercase_		) - 10

def 				_lowerCAmelCase   (     lowercase_		):
						return sum(non_bouncy_exact(lowercase_		) for i in range(1	,			n + 1		)		)

def 				_lowerCAmelCase   (     lowercase_ = 100		):
						return non_bouncy_upto(lowercase_		)


if __name__ == "__main__":
				print(f'''{solution() = }''')





