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

if n == 0:
    print(0)
else:
    blocks = 1
    prev = s[0]
    for c in s[1:]:
        if c != prev:
            blocks += 1
            prev = c
    if blocks == 1:
        print(1)
    else:
        if s[0] == s[-1]:
            print(blocks - 1)
        else:
            print(blocks)