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
# Binary Indexed Tree (Fenwick Tree)
class BIT():
    def __init__(self, n):
        self.n = n
        self.bit = [0] * (n + 1)

    def add(self, i, value):
        i = i + 1
        while i <= self.n:
            self.bit[i] += value
            i += i & -i

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

    def sum(self, l, r):
        return self._sum(r) - self._sum(l)

n = int(input())
S = input()
q = int(input())
Query = [input().split() for _ in range(q)]

bits = [BIT(n) for i in range(26)]
s = []
for i,c in enumerate(S):
    bits[ord(c) - ord("a")].add(i,1)
    s.append(c)

for q_type,fr,to in Query:
    if q_type == "1":
        i = int(fr)-1
        bits[ord(s[i]) - ord("a")].add(i,-1)
        bits[ord(to) - ord("a")].add(i,1)
        s[i] = to
    else:
        l,r = int(fr)-1,int(to)
        tmp = 0
        for i in range(26):
            if bits[i].sum(l,r):
                tmp += 1
        print(tmp)

