Problem: Mahmoud and Ehab solved Dr. Evil's questions so he gave them the password of the door of the evil land. When they tried to open the door using it, the door gave them a final question to solve before they leave (yes, the door is digital, Dr. Evil is modern). If they don't solve it, all the work will be useless and they won't leave the evil land forever. Will you help them?

Mahmoud and Ehab are given n strings s1, s2, ... , sn numbered from 1 to n and q queries, Each query has one of the following forms:

  * 1 a b (1 ≤ a ≤ b ≤ n), For all the intervals [l;r] where (a ≤ l ≤ r ≤ b) find the maximum value of this expression:

(r - l + 1) * LCP(sl, sl + 1, ... , sr - 1, sr) where LCP(str1, str2, str3, ... ) is the length of the longest common prefix of the strings str1, str2, str3, ... .

  * 2 x y (1 ≤ x ≤ n) where y is a string, consisting of lowercase English letters. Change the string at position x to y.

Input

The first line of input contains 2 integers n and q (1 ≤ n ≤ 105, 1 ≤ q ≤ 105) – The number of strings and the number of queries, respectively.

The second line contains n strings stri consisting of lowercase English letters.

The next q lines describe the queries and may have one of the 2 forms:

  * 1 a b (1 ≤ a ≤ b ≤ n).
  * 2 x y (1 ≤ x ≤ n), where y is a string consisting of lowercase English letters.



the total length of all strings in input won't exceed 105

Output

For each query of first type output its answer in a new line.

Example

Input

5 9
mahmoud mahmoudbadawy drmahmoud drevil mahmoud
1 1 5
1 1 2
1 2 3
2 3 mahmoud
2 4 mahmoud
2 2 mahmouu
1 1 5
1 2 3
1 1 1


Output

14
14
13
30
12
7

Solution (in JAVA):

Solution:
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Iterator;
import java.io.BufferedWriter;
import java.util.Collection;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Jialin Ouyang (Jialin.Ouyang@gmail.com)
 */
public class Main {
  public static void main(String[] args) {
    InputStream inputStream = System.in;
    OutputStream outputStream = System.out;
    QuickScanner in = new QuickScanner(inputStream);
    QuickWriter out = new QuickWriter(outputStream);
    TaskF solver = new TaskF();
    solver.solve(1, in, out);
    out.close();
  }

  static class TaskF {
    int n;
    int query;
    String[] s;
    int[] H;
    IntMaxIntervalTree maxIT;
    TaskF.AreaIT areaIT;

    public void solve(int testNumber, QuickScanner in, QuickWriter out) {
      n = in.nextInt();
      query = in.nextInt();
      s = in.next(n);
      initH();
      initMaxIT();
      initAreaIT();
      for (int remQ = query; remQ > 0; --remQ) {
        int op = in.nextInt();
        if (op == 1) {
          int lower = in.nextInt() - 1;
          int upper = in.nextInt();
          out.println(calc(lower, upper));
        } else {
          int idx = in.nextInt() - 1;
          s[idx] = in.next();
          update(idx);
        }
      }
    }

    void initH() {
      H = new int[n - 1];
      for (int i = 1; i < n; ++i) H[i - 1] = calcLCP(s[i - 1], s[i]);
    }

    int calcLCP(String a, String b) {
      int length = Math.min(a.length(), b.length());
      for (int i = 0; i < length; ++i)
        if (a.charAt(i) != b.charAt(i)) {
          return i;
        }
      return length;
    }

    void initMaxIT() {
      int[] initLength = new int[n];
      for (int i = 0; i < n; ++i) initLength[i] = s[i].length();
      maxIT = new IntMaxIntervalTree(n);
      maxIT.init(n, initLength);
    }

    void initAreaIT() {
      areaIT = new TaskF.AreaIT(n - 1);
      areaIT.init(n - 1, H);
    }

    int calc(int lower, int upper) {
      int res = maxIT.calc(lower, upper);
      if (lower < upper) {
        res = Math.max(res, areaIT.calc(lower, upper - 1));
      }
      return res;
    }

    void update(int idx) {
      maxIT.update(idx, s[idx].length());
      if (n == 1) return;
      int lower, upper;
      if (idx == 0) {
        H[idx] = calcLCP(s[idx], s[idx + 1]);
        lower = idx;
        upper = idx + 1;
      } else if (idx == n - 1) {
        H[idx - 1] = calcLCP(s[idx - 1], s[idx]);
        lower = idx - 1;
        upper = idx;
      } else {
        H[idx - 1] = calcLCP(s[idx - 1], s[idx]);
        H[idx] = calcLCP(s[idx], s[idx + 1]);
        lower = idx - 1;
        upper = idx + 1;
      }
      areaIT.update(lower, upper);
    }

    static class AreaIT extends AbstractIntervalTree {
      int[] H;
      IntArrayList[] leftH;
      IntArrayList[] leftD;
      IntArrayList[] rightH;
      IntArrayList[] rightD;
      int[] best;

      public AreaIT(int leafCapacity) {
        super(leafCapacity);
      }


      public void createStorage(int nodeCapacity) {
        leftH = new IntArrayList[nodeCapacity];
        leftD = new IntArrayList[nodeCapacity];
        rightH = new IntArrayList[nodeCapacity];
        rightD = new IntArrayList[nodeCapacity];
        best = new int[nodeCapacity];
        for (int i = 0; i < nodeCapacity; ++i) {
          leftH[i] = new IntArrayList();
          leftD[i] = new IntArrayList();
          rightH[i] = new IntArrayList();
          rightD[i] = new IntArrayList();
        }
      }


      public void initLeaf(int nodeIdx, int idx) {
        leftH[nodeIdx].clear();
        leftD[nodeIdx].clear();
        leftH[nodeIdx].add(H[idx]);
        leftD[nodeIdx].add(1);
        rightH[nodeIdx].clear();
        rightD[nodeIdx].clear();
        rightH[nodeIdx].add(H[idx]);
        rightD[nodeIdx].add(1);
        best[nodeIdx] = H[idx] << 1;
      }


      public void merge(int leftIdx, int rightIdx, int idx) {
        mergeOneSide(
            leftH[idx], leftD[idx],
            leftH[leftIdx], leftD[leftIdx],
            leftH[rightIdx], leftD[rightIdx]);
        mergeOneSide(
            rightH[idx], rightD[idx],
            rightH[rightIdx], rightD[rightIdx],
            rightH[leftIdx], rightD[leftIdx]);
        best[idx] = Math.max(Math.max(Math.max(Math.max(
            best[leftIdx],
            best[rightIdx]),
            calcTwoSide(
                rightH[leftIdx], rightD[leftIdx],
                leftH[rightIdx], leftD[rightIdx])),
            calcOneSide(leftH[idx], leftD[idx])),
            calcOneSide(rightH[idx], rightD[idx]));
      }


      public void copyForCalc(int sourceIdx, int destIdx) {
        leftD[destIdx].clear();
        leftD[destIdx].addAll(leftD[sourceIdx]);
        leftH[destIdx].clear();
        leftH[destIdx].addAll(leftH[sourceIdx]);
        rightD[destIdx].clear();
        rightD[destIdx].addAll(rightD[sourceIdx]);
        rightH[destIdx].clear();
        rightH[destIdx].addAll(rightH[sourceIdx]);
        best[destIdx] = best[sourceIdx];
      }


      public void clearNode(int idx) {
        leftD[idx].clear();
        leftH[idx].clear();
        rightD[idx].clear();
        rightH[idx].clear();
        best[idx] = 0;
      }

      public void init(int n, int[] H) {
        this.H = H;
        super.init(n);
      }

      public void update(int lower, int upper) {
        for (int i = lower; i < upper; ++i) {
          initLeaf(i + leafCnt(), i);
        }
        populateRangeUpdateToRoot(lower, upper);
      }

      public int calc(int lower, int upper) {
        calcRange(lower, upper);
        return best[0];
      }

      private void mergeOneSide(
          IntArrayList resH, IntArrayList resD,
          IntArrayList leftH, IntArrayList leftD,
          IntArrayList rightH, IntArrayList rightD) {

        resH.clear();
        resD.clear();
        resH.addAll(leftH);
        resD.addAll(leftD);
        for (int i = 0; i < rightH.size; ++i) {
          int h = rightH.get(i);
          int d = rightD.get(i);
          if (h >= resH.peekLast()) {
            resD.add(resD.pollLast() + d);
          } else {
            resH.add(h);
            resD.add(d);
          }
        }
      }

      private int calcOneSide(IntArrayList H, IntArrayList D) {
        int sumD = 0;
        int res = 0;
        for (int i = 0; i < H.size; ++i) {
          sumD += D.get(i);
          res = Math.max(res, H.get(i) * (sumD + 1));
        }
        return res;
      }

      private int calcTwoSide(
          IntArrayList rightH, IntArrayList rightD,
          IntArrayList leftH, IntArrayList leftD) {

        int i = 0, j = 0;
        int sumD = 0;
        int res = 0;
        while (i < rightH.size && j < leftH.size) {
          int rh = rightH.get(i), lh = leftH.get(j);
          if (rh > lh) {
            sumD += rightD.get(i++);
            res = Math.max(res, rh * (sumD + 1));
          } else {
            sumD += leftD.get(j++);
            res = Math.max(res, lh * (sumD + 1));
          }
        }
        for (; i < rightH.size; ++i) {
          sumD += rightD.get(i);
          res = Math.max(res, rightH.get(i) * (sumD + 1));
        }
        for (; j < leftH.size; ++j) {
          sumD += leftD.get(j);
          res = Math.max(res, leftH.get(j) * (sumD + 1));
        }
        return res;
      }

    }

  }

  static abstract class AbstractIntervalTree implements Displayable {
    private int nodeCapacity;
    private int leafCnt;
    private int[] rangeLower;
    private int[] rangeUpper;
    private IntArrayList calcIdxInTree;
    private IntArrayList calcIdxInTreeAppendix;

    public abstract void createStorage(int nodeCapacity);

    public abstract void initLeaf(int idxInTree, int idx);

    public abstract void merge(int leftIdxInTree, int rightIdxInTree, int idxInTree);

    public abstract void copyForCalc(int fromIdxInTree, int toIdxInTree);

    public abstract void clearNode(int idx);

    public AbstractIntervalTree(int leafCapacity) {
      calcIdxInTree = new IntArrayList();
      calcIdxInTreeAppendix = new IntArrayList();
      nodeCapacity = leafCapacity << 1;
      rangeLower = new int[nodeCapacity + 2];
      rangeUpper = new int[nodeCapacity + 2];
      createStorage(nodeCapacity + 2);
    }

    public void init(int n) {
      this.leafCnt = n;
      for (int i = 0; i < n; ++i) {
        rangeLower[n + i] = i;
        rangeUpper[n + i] = i + 1;
        initLeaf(i + leafCnt, i);
      }
      for (int i = n - 1; i > 0; --i) {
        int left = i << 1, right = left | 1;
        if (rangeUpper[left] == rangeLower[right]) {
          rangeLower[i] = rangeLower[left];
          rangeUpper[i] = rangeUpper[right];
          merge(left, right, i);
        } else {
          rangeLower[i] = n;
          rangeUpper[i] = -1;
        }
      }
    }

    public void populateRangeUpdateToRoot(int lower, int upper) {
      lower = (lower + leafCnt) >> 1;
      upper = (upper - 1 + leafCnt) >> 1;
      for (; lower > 0 && lower <= upper; lower >>= 1, upper >>= 1) {
        for (int idxInTree = lower; idxInTree <= upper; ++idxInTree)
          if (isValidNode(idxInTree)) {
            merge(idxInTree);
          }
      }
      for (; upper > 0 && isValidNode(upper); upper >>= 1) {
        merge(upper);
      }
    }

    public void calcRange(int lower, int upper) {
      if (lower >= upper) {
        clearNode(0);
        return;
      }
      calcIdxInTree.clear();
      calcIdxInTreeAppendix.clear();
      for (lower += leafCnt, upper += leafCnt; lower < upper; lower >>= 1, upper >>= 1) {
        if ((lower & 1) > 0) {
          if (isValidNode(lower)) calcIdxInTree.add(lower);
          ++lower;
        }
        if ((upper & 1) > 0) {
          if (isValidNode(--upper)) calcIdxInTreeAppendix.add(upper);
        }
      }
      calcIdxInTreeAppendix.reverse();
      calcIdxInTree.addAll(calcIdxInTreeAppendix);
      int idxInTree = calcIdxInTree.get(0);
      int resIdxInTree = nodeCapacity;
      copyForCalc(idxInTree, resIdxInTree);
      rangeLower[resIdxInTree] = rangeLower[idxInTree];
      rangeUpper[resIdxInTree] = rangeUpper[idxInTree];
      for (int i = 1; i < calcIdxInTree.size; ++i, resIdxInTree ^= 1) {
        idxInTree = calcIdxInTree.get(i);
        merge(resIdxInTree, idxInTree, resIdxInTree ^ 1);
        rangeLower[resIdxInTree ^ 1] = rangeLower[resIdxInTree];
        rangeUpper[resIdxInTree ^ 1] = rangeUpper[idxInTree];
      }
      copyForCalc(resIdxInTree, 0);
    }

    public int leafCnt() {
      return leafCnt;
    }

    public int idxInTree(int idx) {
      return idx + leafCnt;
    }

    public boolean isValidNode(int idxInTree) {
      return rangeLower[idxInTree] < rangeUpper[idxInTree];
    }

    private void merge(int idxInTree) {
      merge(idxInTree << 1, (idxInTree << 1) | 1, idxInTree);
    }

  }

  static interface IntCollection {
  }

  static class IntMaxIntervalTree extends AbstractIntervalTree {
    private int[] values;
    private int[] maxValues;

    public IntMaxIntervalTree(int leafCapacity) {
      super(leafCapacity);
    }


    public void init(int n) {
      throw new UnsupportedOperationException();
    }


    public void createStorage(int nodeCapacity) {
      maxValues = new int[nodeCapacity];
    }


    public void initLeaf(int idxInTree, int idx) {
      maxValues[idxInTree] = values[idx];
    }


    public void merge(int leftIdxInTree, int rightIdxInTree, int idxInTree) {
      maxValues[idxInTree] = Math.max(
          maxValues[leftIdxInTree], maxValues[rightIdxInTree]);
    }


    public void copyForCalc(int fromIdxInTree, int toIdxInTree) {
      maxValues[toIdxInTree] = maxValues[fromIdxInTree];
    }


    public void clearNode(int idxInTree) {
      maxValues[idxInTree] = Integer.MIN_VALUE;
    }

    public void init(int n, int[] values) {
      this.values = values;
      super.init(n);
    }

    public void update(int idx, int value) {
      maxValues[idxInTree(idx)] = value;
      populateRangeUpdateToRoot(idx, idx + 1);
    }

    public int calc(int lower, int upper) {
      calcRange(lower, upper);
      return maxValues[0];
    }

  }

  static interface Displayable {
  }

  static class IntArrayList implements Displayable, IntCollection, Iterable<Integer> {
    private static final int[] EMPTY = {};
    public int[] values;
    public int size;

    public IntArrayList() {
      values = EMPTY;
      clear();
    }

    public IntArrayList(int capacity) {
      values = new int[IntUtils.nextPow2(capacity)];
      clear();
    }

    public IntArrayList(Collection<Integer> collection) {
      this(collection.size());
      addAll(collection);
    }


    public void clear() {
      size = 0;
    }


    public void add(int value) {
      ensureCapacity(size + 1);
      addInternal(value);
    }


    public void addAll(Collection<Integer> values) {
      ensureCapacity(size + values.size());
      for (int value : values) {
        addInternal(value);
      }
    }

    public void addAll(IntArrayList values) {
      ensureCapacity(size + values.size);
      for (int i = 0; i < values.size; ++i) {
        addInternal(values.get(i));
      }
    }

    public int peekLast() {
      return values[size - 1];
    }

    public int pollLast() {
      return values[--size];
    }

    public int get(int idx) {
      if (idx >= size) throw new ArrayIndexOutOfBoundsException();
      return values[idx];
    }

    public void reverse() {
      IntArrayUtils.reverse(values, 0, size);
    }

    public void ensureCapacity(int capacity) {
      if (capacity <= values.length) return;
      int[] newValues = new int[IntUtils.nextPow2(capacity)];
      for (int i = 0; i < size; ++i) {
        newValues[i] = values[i];
      }
      values = newValues;
    }


    public Iterator<Integer> iterator() {
      return new Iterator<Integer>() {
        private int i = 0;


        public boolean hasNext() {
          return i < size;
        }


        public Integer next() {
          return values[i++];
        }
      };
    }

    private void addInternal(int value) {
      values[size++] = value;
    }

  }

  static class IntArrayUtils {
    public static void reverse(int[] values, int fromIdx, int toIdx) {
      for (int i = fromIdx, j = toIdx - 1; i < j; ++i, --j) {
        swap(values, i, j);
      }
    }

    public static void swap(int[] values, int uIdx, int vIdx) {
      if (uIdx == vIdx) return;
      values[uIdx] ^= values[vIdx];
      values[vIdx] ^= values[uIdx];
      values[uIdx] ^= values[vIdx];
    }

  }

  static class QuickScanner {
    private static final int BUFFER_SIZE = 1024;
    private InputStream stream;
    private byte[] buffer;
    private int currentPosition;
    private int numberOfChars;

    public QuickScanner(InputStream stream) {
      this.stream = stream;
      this.buffer = new byte[BUFFER_SIZE];
      this.currentPosition = 0;
      this.numberOfChars = 0;
    }

    public String next() {
      int b = nextNonSpaceChar();
      StringBuilder res = new StringBuilder();
      do {
        res.appendCodePoint(b);
        b = nextChar();
      } while (!isSpaceChar(b));
      return res.toString();
    }

    public String[] next(int n) {
      String[] res = new String[n];
      next(n, res);
      return res;
    }

    public void next(int n, String[] res) {
      for (int i = 0; i < n; ++i) {
        res[i] = next();
      }
    }

    public int nextInt() {
      int c = nextNonSpaceChar();
      boolean positive = true;
      if (c == '-') {
        positive = false;
        c = nextChar();
      }
      int res = 0;
      do {
        if (c < '0' || '9' < c) throw new RuntimeException();
        res = res * 10 + c - '0';
        c = nextChar();
      } while (!isSpaceChar(c));
      return positive ? res : -res;
    }

    public int nextNonSpaceChar() {
      int res = nextChar();
      for (; isSpaceChar(res) || res < 0; res = nextChar()) ;
      return res;
    }

    public int nextChar() {
      if (numberOfChars == -1) {
        throw new RuntimeException();
      }
      if (currentPosition >= numberOfChars) {
        currentPosition = 0;
        try {
          numberOfChars = stream.read(buffer);
        } catch (Exception e) {
          throw new RuntimeException(e);
        }
        if (numberOfChars <= 0) {
          return -1;
        }
      }
      return buffer[currentPosition++];
    }

    public boolean isSpaceChar(int c) {
      return c == ' ' || c == '\t' || isEndOfLineChar(c);
    }

    public boolean isEndOfLineChar(int c) {
      return c == '\n' || c == '\r' || c < 0;
    }

  }

  static class QuickWriter {
    private final PrintWriter writer;

    public QuickWriter(OutputStream outputStream) {
      this.writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }

    public QuickWriter(Writer writer) {
      this.writer = new PrintWriter(writer);
    }

    public void print(Object... objects) {
      for (int i = 0; i < objects.length; ++i) {
        if (i > 0) {
          writer.print(' ');
        }
        writer.print(objects[i]);
      }
    }

    public void println(Object... objects) {
      print(objects);
      writer.print('\n');
    }

    public void close() {
      writer.close();
    }

  }

  static class IntUtils {
    public static boolean isPow2(int n) {
      return n > 0 && (n & (n - 1)) == 0;
    }

    public static int nextPow2(int n) {
      if (n < 1) return 1;
      return isPow2(n) ? n : Integer.highestOneBit(n) << 1;
    }

  }
}