s=input("Enter the string:")
max1=0
curr_max=0
for i in range(len(s)):
	if s[i]=='(':
	 curr_max+=1
	 if(curr_max>max1):
	  max1=curr_max
	elif s[i]==')':
	 curr_max-=1
if curr_max==0:
	print(max1)
else : 
	print("mismatch")
	print(max1)