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 RSQ_add(i, x, y):
    while True:
        if i > n:
            break
        BIT[y][i] += x
        i += i & -i

def RSQ_getsum(i, x):
    s = 0
    while True:
        if i <= 0:
            break
        s += BIT[x][i]
        i -= i & -i
    return s

n = int(input())
s = list(input())
q = int(input())
BIT = [[0] * (n + 1) for _ in range(26)]
for i in range(n):
    y = ord(s[i]) - 97
    RSQ_add(i + 1, 1, y)
for _ in range(q):
    com, a, b = map(str, input().split())
    com, a = int(com), int(a)
    if com == 1:
        RSQ_add(a, -1, ord(s[a - 1]) - 97)
        RSQ_add(a, 1, ord(b) - 97)
        s[a - 1] = b
    else:
        b = int(b)
        ans = 0
        for i in range(26):
            if RSQ_getsum(b, i) - RSQ_getsum(a - 1, i) >= 1:
                ans += 1
        print(ans)