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 string import ascii_lowercase
import sys


def input():
    return sys.stdin.readline().strip()


class BIT:
    def __init__(self, n):
        self.n = n
        self.data = [0] * (n + 1)
        self.k_init = 2 ** (self.n - 1).bit_length()

    def sum(self, i):
        s = 0
        while i > 0:
            s += self.data[i]
            i -= i & -i
        return s

    def add(self, i, x):
        while i <= self.n:
            self.data[i] += x
            i += i & -i


n = int(input())
s = input()
q = int(input())

bits = {c: BIT(n) for c in ascii_lowercase}
[bits[c].add(i, 1) for i, c in enumerate(s, 1)]
queries = (input().split() for _ in range(q))

for q_type, *q in queries:
    if q_type == '1':
        iq = int(q[0])
        cq = q[1]
        for b in bits.values():
            if b.sum(iq) - b.sum(iq - 1) == 1:
                b.add(iq, -1)
                break
        bits[cq].add(iq, 1)
    else:
        l, r = map(int, q)
        print(sum([bool(v.sum(r) - v.sum(l - 1) > 0) for v in bits.values()]))
