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

if n == 0:
    print(0)
    exit()

# Calculate the number of runs
runs = 1
for i in range(1, n):
    if s[i] != s[i-1]:
        runs += 1

if runs == 1:
    print(1)
else:
    if s[0] == s[-1]:
        print(runs - 1)
    else:
        print(runs)