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 ctoi(x):
    return ord(x)-ord("a")
n = int(input())
s = list(input())
q = int(input())
bit = [[0]*(n+1) for _ in range(26)]

def update(pos,a,x):
    while pos<=n:
        bit[a][pos] += x
        pos += pos&(-pos)

def query(pos):
    ret=[0]*26
    for i in range(26):
        tmp=0
        p=pos
        while p>0:
            tmp+=bit[i][p]
            p-=p&(-p)
        ret[i]=tmp
    return ret

for i in range(n):
    update(i+1,ctoi(s[i]),1)

for _ in range(q):
    flag,a,b = input().split()
    flag=int(flag)
    a=int(a)
    if flag==1:
        if s[a-1]==b:
            continue
        else:
            update(a,ctoi(s[a-1]),-1)
            update(a,ctoi(b),1)
            s[a-1]=b
    else:
        b=int(b)
        c1 = query(b)
        c2 = query(a-1)
        ans = 0
        for i in range(26):
            if c1[i]-c2[i]>0:
                ans += 1
        print(ans)