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
import sys
from bisect import bisect_left, bisect_right, insort

sr = lambda: sys.stdin.readline().rstrip()
ir = lambda: int(sr())
lr = lambda: list(map(int, sr().split()))

N = ir()
S = list('-' + sr())
d = [[] for _ in range(26)]
for i in range(1, N+1):
    s = S[i]
    o = ord(s) - ord('a')
    insort(d[o], i)

Q = ir()
for _ in range(Q):
    q, a, b = sr().split()
    if q == '1':
        a = int(a)
        if S[a] == b:
            continue
        prev = ord(S[a]) - ord('a')
        d[prev].pop(bisect_left(d[prev], a))
        next = ord(b) - ord('a')
        insort(d[next], a)
        S[a] = b
    else:
        a = int(a); b = int(b)
        ans = 0
        for alpha in range(26):
            if bisect_right(d[alpha], b) - bisect_left(d[alpha], a) >= 1:
                ans += 1
        print(ans)

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