n = int(input())
s = input().strip()

if n == 0:
    print(0)
else:
    transitions = 0
    for i in range(1, n):
        if s[i] != s[i-1]:
            transitions += 1

    valleys = 0
    for i in range(1, n-1):
        if s[i-1] == s[i+1] and s[i-1] != s[i]:
            valleys += 1

    print(transitions + 1 - valleys)