# AOJ 2831: Check answers
# Python3 2018.7.12 bal4u

n = int(input())
if n == 0: print(0)
else:
	s = input()
	ans = 1
	for i in range(1, len(s)):
		if s[i-1] == 'x' and s[i] == 'x': break
		ans += 1
	print(ans)

