You are given a string S of length N consisting of lowercase English letters.

Process Q queries of the following two types:

* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).

Constraints

* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.

Input

Input is given from Standard Input in the following format:


N
S
Q
Query_1
\vdots
Query_Q


Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:


1 i_q c_q



2 l_q r_q


Output

For each query of type 2, print a line containing the answer.

Example

Input

7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7


Output

3
1
5
# https://atcoder.jp/contests/abc157/tasks/abc157_e

from string import ascii_lowercase
from bisect import bisect_left, insort
from collections import defaultdict

N = int(input())
S = list(input())
Q = int(input())

locs = {c: [] for c in ascii_lowercase}
for i in range(N):
    locs[S[i]].append(i + 1)

for _ in range(Q):
    qt, l, r = input().split()
    l = int(l)
    if int(qt) == 1:
        if S[l - 1] != r:
            locs[S[l - 1]].remove(l)
            S[l - 1] = r
            insort(locs[r], l)
    else:
        count = 0
        r = int(r)
        for ch in ascii_lowercase:
            if len(locs[ch]) > 0:
                left = bisect_left(locs[ch], l)
                if left != len(locs[ch]):
                    if locs[ch][left] <= r:
                        count += 1

        print(count)