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

    def total(self, i):
        res = 0
        while i:
            res += self.data[i]
            i -= i & -i
        return res

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


N = int(input())
bit = BIT(N)
for i, c in enumerate(input()):
    ind = ord(c) - ord("a")
    bit.add(i + 1, 1 << (ind * 20))
Q = int(input())
for _ in range(Q):
    parts = input().split()
    if parts[0] == "1":
        ind = int(parts[1])
        nval = 1 << ((ord(parts[2]) - ord("a")) * 20)
        val = bit.total(ind) - bit.total(ind - 1)
        bit.add(ind, nval - val)
    else:
        l, r = map(int, parts[1:])
        val = bit.total(r) - bit.total(l - 1)
        mask = (1 << 20) - 1
        ans = 0
        while val:
            if val & mask:
                ans += 1
            val >>= 20
        print(ans)
