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

def bitadd(a,w,bit): #aにwを加える(1-origin)
 
    x = a
    while x <= (len(bit)-1):
        bit[x] += w
        x += x & (-1 * x)
 
def bitsum(a,bit): #ind 1～aまでの和を求める

    if a == 0:
        return 0
 
    ret = 0
    x = a
    while x > 0:
        ret += bit[x]
        x -= x & (-1 * x)
    return ret


alp = "abcdefghijklmnopqrstuvwxyz"

al = {}

for i in range(26):
    al[alp[i]] = i

N = int(input())

BITS = [ [0] * (N+1) for i in range(26) ]

S = list(input())

for i in range(N):

    bitadd(i+1,1,BITS[al[S[i]]])

Q = int(input())
for i in range(Q):

    qs,x,y = input().split()
    qs = int(qs)
    
    if qs == 1:
        x = int(x)
        bitadd(x,-1,BITS[al[S[x-1]]])
        bitadd(x,1,BITS[al[y]])
        S[x-1] = y

    else:
        x = int(x)
        y = int(y)

        ans = 0
        for j in range(26):
            ans += min(1 , bitsum(y,BITS[j]) - bitsum(x-1,BITS[j]))

        print (ans)
