n = int(input())
l=[]
for i in range(n):
    l.append(input())

s = [[0,0,0] for i in range(n)]
if l[0] == 'H':
    s[0][0] = 1
elif l[0] == 'P':
    s[0][1] = 1
else:
    s[0][2] = 1
for i in range(1,n):
    s[i][0] = s[i-1][0]
    s[i][1] = s[i-1][1]
    s[i][2] = s[i-1][2]
    if l[i] == 'H':
        s[i][0] += 1
    elif l[i] == 'P':
        s[i][1] += 1
    else:
        s[i][2] += 1
ans = 0
for i in range(1,n-1):
    temp1 = max(s[i])
    temp2 = max([b-a for a,b in zip(s[i], s[n-1])])
    ans = max(ans, temp1 + temp2)
print(ans)