750 B | 750 chars
import sys
from math import sqrt, pi, sin, cos, factorial, ceil, floor
from datetime import datetime, timedelta
# sys.setrecursionlimit(10**7)
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
prt = 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()
k = list("RAKTAS")
ans = 0
for i in s:
ans += 1
if i in k:
k.pop(k.index(i))
if len(k) == 0:
break
prt(ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()