import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        char[] inputs = sc.next().toCharArray();
        int q = sc.nextInt();
        SegmentTree st = new SegmentTree(n);
        for (int i = 0; i < n; i++) {
            st.add(i, inputs[i] - 'A', 1);
        }
        st.allCalc(0);
        StringBuilder sb = new StringBuilder();
        while (q-- > 0) {
            if (sc.nextInt() == 1) {
                int idx = sc.nextInt() - 1;
                char c = sc.next().charAt(0);
                st.add(idx, inputs[idx] - 'A', -1);
                inputs[idx] = c;
                st.add(idx, inputs[idx] - 'A', 1);
                st.calc(idx);
            } else {
                int left = sc.nextInt() - 1;
                int right = sc.nextInt();
                sb.append(st.getMMA(left, right)).append("\n");
            }
        }
        System.out.print(sb);
    }
    
    static class SegmentTree {
        int size;
        int[][] counts;
        long[][] ma;
        long[] mma;
        
        public SegmentTree(int x) {
            size = 1;
            while (size < x) {
                size <<= 1;
            }
            counts = new int[size * 2 - 1][26];
            ma = new long[size * 2 - 1][26];
            mma = new long[size * 2 - 1];
        }
        
        public void add(int idx, int c, int v) {
            counts[size + idx - 1][c] += v;
        }
        
        public void allCalc(int idx) {
            if (idx >= size - 1) {
                return;
            }
            allCalc(idx * 2 + 1);
            allCalc(idx * 2 + 2);
            coreCalc(idx);
        }
        
        public void calc(int idx) {
            calcTree((size + idx - 2) / 2);
        }
        
        public void calcTree(int idx) {
            coreCalc(idx);
            if (idx > 0) {
                calcTree((idx - 1) / 2);
            }
        }
        
        private void coreCalc(int idx) {
            mma[idx] = mma[idx * 2 + 1] + mma[idx * 2 + 2];
            for (int i = 0; i < 26; i++) {
                counts[idx][i] = counts[idx * 2 + 1][i] + counts[idx * 2 + 2][i];
                mma[idx] += counts[idx * 2 + 1][i] * ma[idx * 2 + 2][i];
                ma[idx][i] = ma[idx * 2 + 1][i] + ma[idx * 2 + 2][i];
                for (int j = 0; j < 26; j++) {
                    if (i == j) {
                        continue;
                    }
                    ma[idx][i] += counts[idx * 2 + 1][i] * counts[idx * 2 + 2][j]; 
                    mma[idx] += (counts[idx * 2 + 1][i] - 1) * counts[idx * 2 + 1][i] / 2 * counts[idx * 2 + 2][j];
                }
            }
        }
        
        public long getMMA(int left, int right) {
            MMA x = getMMA(0, left, right, 0, size);
            return x.mma;
        }
        
        private MMA getMMA(int idx, int left, int right, int min, int max) {
            if (left <= min && max <= right) {
                return new MMA(counts[idx], ma[idx], mma[idx]);
            }
            if (left >= max || right <= min) {
                return MMA.INI;
            }
            return getMMA(idx * 2 + 1, left, right, min, (min + max) / 2).merge(getMMA(idx * 2 + 2, left, right, (min + max) / 2, max));
        }
    }
    
    static class MMA {
        int[] counts;
        long[] ma;
        long mma;
        
        static MMA INI = new MMA();
        
        public MMA(int[] counts, long[] ma, long mma) {
            this.counts = counts;
            this.ma = ma;
            this.mma = mma;
        }
        
        public MMA() {
            this(new int[26], new long[26], 0);
        }
        
        public MMA merge(MMA x) {
            MMA ans = new MMA();
            ans.mma = mma + x.mma;
            for (int i = 0; i < 26; i++) {
                ans.counts[i] = counts[i] + x.counts[i];
                ans.mma += counts[i] * x.ma[i];
                ans.ma[i] = ma[i] + x.ma[i];
                for (int j = 0; j < 26; j++) {
                    if (i == j) {
                        continue;
                    }
                    ans.ma[i] += counts[i] * x.counts[j];
                    ans.mma += (counts[i] - 1) * counts[i] / 2 * x.counts[j];
                }
            }
            return ans;
        }
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}