#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

struct S {
  ll v01, v02, v03, v12, v13, v23;
};

S op(const S& x, const S& y) {
  return S{
    x.v01 + y.v01,
    x.v02 + x.v01 * y.v12 + y.v02,
    x.v03 + x.v02 * y.v23 + x.v01 * y.v13 + y.v03,
    x.v12 + y.v12,
    x.v13 + x.v12 * y.v23 + y.v13,
    x.v23 + y.v23
  };
}
S e() {
  return S{0, 0, 0, 0, 0, 0};
}

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  string s;
  cin >> n >> s;
  S match{1, 0, 0, 1, 0, 0}, unmatch{0, 0, 0, 0, 0, 1};
  vector<segtree<S, op, e>> seg;
  rep(c, 26) {
    vector<S> init(n);
    rep(i, n) {
      init[i] = s[i] - 'A' == c ? match : unmatch;
    }
    seg.emplace_back(init);
  }
  int q;
  cin >> q;
  while (q--) {
    int op;
    cin >> op;
    if (op == 1) {
      int x;
      char c;
      cin >> x >> c;
      x--;
      seg[s[x] - 'A'].set(x, unmatch);
      s[x] = c;
      seg[s[x] - 'A'].set(x, match);
    } else {
      int l, r;
      cin >> l >> r;
      l--;
      ll ans = 0;
      rep(c, 26) ans += seg[c].prod(l, r).v03;
      cout << ans << '\n';
    }
  }
}