# AOJ 2831: Check answers
# Python3 2018.7.12 bal4u

n = int(input())
if n == 0: print(0)
else:
	s = input()
	ans = 1; pre = s[0]
	for t in s[1:]:
		if pre == 'x' and t == 'x': break
		pre = t; ans += 1
	print(ans)

