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()


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


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


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

bits = {c: [0] * (n + 1) for c in ascii_lowercase}
[add_b(bits[c], i, 1) for i, c in enumerate(s, 1)]

for q_type, *q in (input().split() for _ in range(q)):
    if q_type == '1':
        iq = int(q[0])
        cq = q[1]
        for b in bits.values():
            if sum_b(b, iq) - sum_b(b, iq - 1) == 1:
                add_b(b, iq, -1)
                break
        add_b(bits[cq], iq, 1)
    else:
        l, r = map(int, q)
        print(sum([bool(sum_b(b, r) - sum_b(b, l - 1) > 0) for b in bits.values()]))
