1.2 KB | 1226 chars
"""
[29145: Можно и отдохнуть](https://www.acmicpc.net/problem/29145)
Tier: Bronze 2
Category: arithmetic, math
"""
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
SYS_INPUT = True
RECURSION_LIMIT = 10 ** 7
SET_RECURSION = False
BLANK = " "
if SET_RECURSION:
sys.setrecursionlimit(RECURSION_LIMIT)
inp = lambda : sys.stdin.readline().rstrip() if SYS_INPUT else input()
mii = lambda : [*map(int,inp().split())]
mfi = lambda : [*map(float,inp().split())]
ii = lambda : int(inp())
fi = lambda : float(inp())
isplit = lambda : inp().split()
p = print
def gcd(a, b): return gcd(b, a % b) if b > 0 else a
def lcm(a, b): return a * b // gcd(a, b)
def solve():
N = ii()
s = inp()
ans = 0
s_cnt = 0
l_cnt = 0
for i in s:
if '0' <= i <='9':
ans += 1
else:
if i == 'K' and s_cnt > 0:
ans += 1
s_cnt -= 1
elif i == 'R' and l_cnt > 0:
ans += 1
l_cnt -= 1
else:
if i == 'K' or i == 'R':
break
if i == 'S':
s_cnt += 1
if i == 'L':
l_cnt += 1
p(ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()