1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
import sys

input = sys.stdin.readline

n = int(input())
s = input()

g = n // 10

ans = 0
for i in range(10):
    if all([t == 'T' for t in s[i*g:(i+1)*g]]):
        ans += 1
       
print(ans)