n=int(input())

L=32
k=26

def op(x,y):
  z=[0]*(k+k+1)
  for i in range(k+k+1):
    z[i]=x[i]+y[i]
  c=0
  for i in range(k):
    c+=x[i]*(x[i]-1)//2
  for i in range(k):
      z[-1]+=(c-x[i]*(x[i]-1)//2)*y[i]
  for i in range(k):
    z[-1]+=x[i]*y[k+i]
  c=0
  for i in range(k):
    c+=y[i]
  for i in range(k):
    z[k+i]+=x[i]*(c-y[i])
  return z

q=[[0]*(k+k+1) for i in range(L*2)]

s=input()
for i in range(n):
  p=L+i
  q[p][ord(s[i])-ord("A")]=1
  p//=2
  while p>0:
    q[p]=op(q[p*2+0],q[p*2+1])
    p//=2

Q=int(input())
for _ in range(Q):
  t,p1,p2=input().split()
  t=int(t)
  if t==1:
    c=p2
    p=L+int(p1)-1
    q[p]=[0]*(k+k+1)
    q[p][ord(c)-ord("A")]=1
    p//=2
    while p>0:
      q[p]=op(q[p*2+0],q[p*2+1])
      p//=2
  if t==2:
    l=L+int(p1)-1
    r=L+int(p2)-1
    pl=[]
    pr=[]
    while l<=r:
      if l%2==1:
        pl+=[l]
        l+=1
      if r%2==0:
        pr+=[r]
        r-=1
      l//=2
      r//=2
    if len(pl)>0 and len(pr)>0 and pl[-1]==pr[-1]:
      pr.pop()
    a=[0]*(k+k+1)
    for p in pl:
      a=op(a,q[p])
    for p in pr[::-1]:
      a=op(a,q[p])
    print(a[-1])