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
import sys

read = sys.stdin.read
readline = sys.stdin.readline


class BIT:
    def __init__(self, n):
        self.n = n
        self.tree = [[0] * (n + 1) for _ in range(26)]

    def bit_query(self, character, idx):
        if idx == 0:
            return 0
        sum_of_query = 0
        while idx > 0:
            sum_of_query += self.tree[character][idx]
            idx -= idx & (-idx)
        return sum_of_query

    def update(self, character, idx, x):
        while idx <= self.n:
            self.tree[character][idx] += x
            idx += idx & (-idx)
        return


N = int(input())
S = [i - 97 for i in map(ord, list(input()))]
S = [-1] + S
Q, *query = map(str, read().split())
bit = BIT(N)
for idx, i in enumerate(S[1:], 1):
    bit.update(i, idx, 1)
for a, b, c in zip(*[iter(query)] * 3):
    b = int(b)
    if a == '1':
        c = ord(c) - 97
        if S[b] == c:
            continue
        bit.update(c, b, 1)
        bit.update(S[b], b, -1)
        S[b] = c
    else:
        c = int(c)
        print(sum(1 for i in range(26) if bit.bit_query(i, c) - bit.bit_query(i, b - 1) > 0))
