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
from bisect import bisect_left, bisect_right

N = int(input())

S = list(input())

Q = int(input())

memo = {chr(ord('a') + i): [] for i in range(26)}

for key,val in enumerate(S):
    memo[val].append(key)

for q in range(Q):
    query = list(input().split())
    if query[0] == '1':
        i, x = int(query[1])-1, query[2]
        now = S[i]
        if now == x:
            continue
        memo[now].remove(i)
        next_i = bisect_left(memo[x], i)
        memo[x].insert(next_i, i)
        S[i] = x
    else:
        start, end = int(query[1])-1, int(query[2])-1
        tmp_cout = 0
        for alf_array in memo.values():
            if len(alf_array) == 0:
                continue
            ss = bisect_left(alf_array, start)
            gg = bisect_right(alf_array, end)
            if gg- ss > 0:
                tmp_cout += 1
        print(tmp_cout)
