import sys int1 = lambda x: int(x) - 1 # input = lambda: sys.stdin.buffer.readline() input = lambda: sys.stdin.readline().rstrip() ii = lambda: int(input()) i1 = lambda: int1(input()) mi = lambda: map(int, input().split()) mi1 = lambda: map(int1, input().split()) li = lambda: list(mi()) li1 = lambda: list(mi1()) lli = lambda n: [li() for _ in range(n)] INF = float("inf") mod = int(1e9 + 7) # mod = 998244353 # https://github.com/tatyam-prime/SortedSet/blob/main/SortedSet.py import math from bisect import bisect_left, bisect_right from typing import Generic, Iterable, Iterator, TypeVar, Union, List T = TypeVar("T") class SortedSet(Generic[T]): BUCKET_RATIO = 50 REBUILD_RATIO = 170 def _build(self, a=None) -> None: "Evenly divide `a` into buckets." if a is None: a = list(self) size = self.size = len(a) bucket_size = int(math.ceil(math.sqrt(size / self.BUCKET_RATIO))) self.a = [ a[size * i // bucket_size : size * (i + 1) // bucket_size] for i in range(bucket_size) ] def __init__(self, a: Iterable[T] = []) -> None: "Make a new SortedSet from iterable. / O(N) if sorted and unique / O(N log N)" a = list(a) if not all(a[i] < a[i + 1] for i in range(len(a) - 1)): a = sorted(set(a)) self._build(a) def __iter__(self) -> Iterator[T]: for i in self.a: for j in i: yield j def __reversed__(self) -> Iterator[T]: for i in reversed(self.a): for j in reversed(i): yield j def __len__(self) -> int: return self.size def __repr__(self) -> str: return "SortedSet" + str(self.a) def __str__(self) -> str: s = str(list(self)) return "{" + s[1 : len(s) - 1] + "}" def _find_bucket(self, x: T) -> List[T]: "Find the bucket which should contain x. self must not be empty." for a in self.a: if x <= a[-1]: return a return a def __contains__(self, x: T) -> bool: if self.size == 0: return False a = self._find_bucket(x) i = bisect_left(a, x) return i != len(a) and a[i] == x def add(self, x: T) -> bool: "Add an element and return True if added. / O(√N)" if self.size == 0: self.a = [[x]] self.size = 1 return True a = self._find_bucket(x) i = bisect_left(a, x) if i != len(a) and a[i] == x: return False a.insert(i, x) self.size += 1 if len(a) > len(self.a) * self.REBUILD_RATIO: self._build() return True def discard(self, x: T) -> bool: "Remove an element and return True if removed. / O(√N)" if self.size == 0: return False a = self._find_bucket(x) i = bisect_left(a, x) if i == len(a) or a[i] != x: return False a.pop(i) self.size -= 1 if len(a) == 0: self._build() return True def lt(self, x: T) -> Union[T, None]: "Find the largest element < x, or None if it doesn't exist." for a in reversed(self.a): if a[0] < x: return a[bisect_left(a, x) - 1] def le(self, x: T) -> Union[T, None]: "Find the largest element <= x, or None if it doesn't exist." for a in reversed(self.a): if a[0] <= x: return a[bisect_right(a, x) - 1] def gt(self, x: T) -> Union[T, None]: "Find the smallest element > x, or None if it doesn't exist." for a in self.a: if a[-1] > x: return a[bisect_right(a, x)] def ge(self, x: T) -> Union[T, None]: "Find the smallest element >= x, or None if it doesn't exist." for a in self.a: if a[-1] >= x: return a[bisect_left(a, x)] def __getitem__(self, x: int) -> T: "Return the x-th element, or IndexError if it doesn't exist." if x < 0: x += self.size if x < 0: raise IndexError for a in self.a: if x < len(a): return a[x] x -= len(a) raise IndexError def index(self, x: T) -> int: "Count the number of elements < x." ans = 0 for a in self.a: if a[-1] >= x: return ans + bisect_left(a, x) ans += len(a) return ans def index_right(self, x: T) -> int: "Count the number of elements <= x." ans = 0 for a in self.a: if a[-1] > x: return ans + bisect_right(a, x) ans += len(a) return ans n = ii() s = list(input()) t = list(input()) se = SortedSet([i for i in range(n) if s[i] != t[i]]) for _ in range(ii()): c, x, y = input().split() x = int(x) - 1 se.discard(x) if c == "S": s[x] = y else: t[x] = y if s[x] != t[x]: se.add(x) if se: i = se[0] #print("<>"[s[i] > t[i]]) else: #print("=") pass