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

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

# Split the string into runs of the same color
runs = []
prev = s[0]
runs.append(prev)
for c in s[1:]:
    if c != prev:
        runs.append(c)
        prev = c

count = len(runs)

# If the first and last runs are the same, subtract one
if len(runs) > 1 and runs[0] == runs[-1]:
    count -= 1

print(count)