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
N = int(input())
S = list(input())
Q = int(input())

l = 2**((N-1).bit_length())
#data = [Counter([]) for i in range(2*l)]
data = [0] * (2*l)

str2bin = lambda x : 1 << (ord(x) - ord('a'))
    
for i in range(N):
    data[l+i] = str2bin(S[i])
for i in range(l-1,0,-1):
    data[i] = data[2*i] | data[2*i+1]

for cnt in range(Q):
    a,b,c = input().split()
    a = int(a)
    b = int(b)
    if a == 1:
        n = l + b - 1
        data[n] = str2bin(c)
        n //= 2
        while n > 0:
            data[n] = data[2*n] | data[2*n+1]
            n = n // 2
    else:
        c = int(c)
        i = b + l -1
        j = c + l
        res = 0
        while j-i > 0:
            if i & 1:
                res |= data[i]
                i += 1
            if j & 1:
                res |= data[j-1]
                j -= 1
            i //= 2
            j //= 2
        print(bin(res).count('1'))

