Problem: Polycarpus just has been out of luck lately! As soon as he found a job in the "Binary Cat" cafe, the club got burgled. All ice-cream was stolen.

On the burglary night Polycarpus kept a careful record of all club visitors. Each time a visitor entered the club, Polycarpus put down character "+" in his notes. Similarly, each time a visitor left the club, Polycarpus put character "-" in his notes. We know that all cases of going in and out happened consecutively, that is, no two events happened at the same time. Polycarpus doesn't remember whether there was somebody in the club at the moment when his shift begun and at the moment when it ended.

Right now the police wonders what minimum number of distinct people Polycarpus could have seen. Assume that he sees anybody coming in or out of the club. Each person could have come in or out an arbitrary number of times.

Input

The only line of the input contains a sequence of characters "+" and "-", the characters are written one after another without any separators. The characters are written in the order, in which the corresponding events occurred. The given sequence has length from 1 to 300 characters, inclusive.

Output

Print the sought minimum number of people

Examples

Input

+-+-+


Output

1


Input

---

Output

3

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.lang.reflect.Constructor;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.InputMismatchException;
import java.util.LinkedList;
import java.util.StringTokenizer;

public class CodeD {
  private static final boolean IN_DEBUG = true;

  static final SuperWriter sw = new SuperWriter(System.out);

  public static void main(String[] args) {
    Scanner sc = new SuperScanner();
    LinkedList<Integer> peopleIn = new LinkedList<Integer>();
    LinkedList<Integer> peopleOut = new LinkedList<Integer>();
    int id = 0;
    for (char c : sc.next().toCharArray()) {
      if (c == '-') {
        if (peopleIn.isEmpty()) {
          peopleOut.add(id++);
        } else {
          peopleOut.add(peopleIn.poll());
        }
      } else {
        if (peopleOut.isEmpty()) {
          peopleIn.add(id++);
        } else {
          peopleIn.add(peopleOut.poll());
        }
      }
    }
    sw.printLine(peopleIn.size() + peopleOut.size());
  }

  static class SuperScanner extends Scanner {
    private InputStream stream;
    private byte[] buf = new byte[8096];
    private int curChar;
    private int numChars;

    public SuperScanner() {
        this.stream = System.in;
    }

    public int read() {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }
    
    public static boolean isWhitespace(int c) {
      return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }
    
    private final StringBuilder sb = new StringBuilder();
    
    @Override
    public String next() {
      int c = read();
      while (isWhitespace(c)) {
          if (c == -1) {
            return null;
          }
          c = read();
      }
      sb.setLength(0);
      do {
          sb.append((char) c);
          c = read();
      } while (!isWhitespace(c));
      return sb.toString();
    }

    @Override
    public int nextInt() {
        int c = read();
        while (isWhitespace(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res = (res << 3) + (res << 1);
            res += c - '0';
            c = read();
        } while (!isWhitespace(c));
        return res * sgn;
    }

    @Override
    public long nextLong() {
        int c = read();
        while (isWhitespace(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        long res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res = (res << 3) + (res << 1);
            res += c - '0';
            c = read();
        } while (!isWhitespace(c));
        return res * sgn;
    }
  }
  
  static class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    public String nextLine() {
      try {
        return br.readLine();
      } catch (Exception e) {
        throw (new RuntimeException());
      }
    }

    public int nextIntOrQuit() {
      Integer n = nextInteger();
      if (n == null) {
        sw.close();
        System.exit(0);
      }
      return n.intValue();
    }

    public String next() {
      while (!st.hasMoreTokens()) {
        String l = nextLine();
        if (l == null)
          return null;
        st = new StringTokenizer(l);
      }
      return st.nextToken();
    }

    public int nextInt() {
      return Integer.parseInt(next());
    }

    public long nextLong() {
      return Long.parseLong(next());
    }

    public double nextDouble() {
      return Double.parseDouble(next());
    }

    public int[] nextIntArray(int n) {
      int[] res = new int[n];
      for (int i = 0; i < res.length; i++)
        res[i] = nextInt();
      return res;
    }

    public long[] nextLongArray(int n) {
      long[] res = new long[n];
      for (int i = 0; i < res.length; i++)
        res[i] = nextLong();
      return res;
    }

    public double[] nextDoubleArray(int n) {
      double[] res = new double[n];
      for (int i = 0; i < res.length; i++)
        res[i] = nextDouble();
      return res;
    }

    public void sortIntArray(int[] array) {
      Integer[] vals = new Integer[array.length];
      for (int i = 0; i < array.length; i++)
        vals[i] = array[i];
      Arrays.sort(vals);
      for (int i = 0; i < array.length; i++)
        array[i] = vals[i];
    }

    public void sortLongArray(long[] array) {
      Long[] vals = new Long[array.length];
      for (int i = 0; i < array.length; i++)
        vals[i] = array[i];
      Arrays.sort(vals);
      for (int i = 0; i < array.length; i++)
        array[i] = vals[i];
    }

    public void sortDoubleArray(double[] array) {
      Double[] vals = new Double[array.length];
      for (int i = 0; i < array.length; i++)
        vals[i] = array[i];
      Arrays.sort(vals);
      for (int i = 0; i < array.length; i++)
        array[i] = vals[i];
    }

    public String[] nextStringArray(int n) {
      String[] vals = new String[n];
      for (int i = 0; i < n; i++)
        vals[i] = next();
      return vals;
    }

    public Integer nextInteger() {
      String s = next();
      if (s == null)
        return null;
      return Integer.parseInt(s);
    }

    public int[][] nextIntMatrix(int n, int m) {
      int[][] ans = new int[n][];
      for (int i = 0; i < n; i++)
        ans[i] = nextIntArray(m);
      return ans;
    }

    public char[][] nextGrid(int r) {
      char[][] grid = new char[r][];
      for (int i = 0; i < r; i++)
        grid[i] = next().toCharArray();
      return grid;
    }

    public static <T> T fill(T arreglo, int val) {
      if (arreglo instanceof Object[]) {
        Object[] a = (Object[]) arreglo;
        for (Object x : a)
          fill(x, val);
      } else if (arreglo instanceof int[])
        Arrays.fill((int[]) arreglo, val);
      else if (arreglo instanceof double[])
        Arrays.fill((double[]) arreglo, val);
      else if (arreglo instanceof long[])
        Arrays.fill((long[]) arreglo, val);
      return arreglo;
    }

    public <T> T[] nextObjectArray(Class<T> clazz, int size) {
      @SuppressWarnings("unchecked")
      T[] result = (T[]) java.lang.reflect.Array.newInstance(clazz, size);
      for (int c = 0; c < 3; c++) {
        Constructor<T> constructor;
        try {
          if (c == 0)
            constructor = clazz.getDeclaredConstructor(Scanner.class,
                Integer.TYPE);
          else if (c == 1)
            constructor = clazz.getDeclaredConstructor(Scanner.class);
          else
            constructor = clazz.getDeclaredConstructor();
        } catch (Exception e) {
          continue;
        }
        try {
          for (int i = 0; i < result.length; i++) {
            if (c == 0)
              result[i] = constructor.newInstance(this, i);
            else if (c == 1)
              result[i] = constructor.newInstance(this);
            else
              result[i] = constructor.newInstance();
          }
        } catch (Exception e) {
          throw new RuntimeException(e);
        }
        return result;
      }
      throw new RuntimeException("Constructor not found");
    }

    public Collection<Integer> wrap(int[] as) {
      ArrayList<Integer> ans = new ArrayList<Integer>();
      for (int i : as)
        ans.add(i);
      return ans;
    }

    public int[] unwrap(Collection<Integer> collection) {
      int[] vals = new int[collection.size()];
      int index = 0;
      for (int i : collection)
        vals[index++] = i;
      return vals;
    }
  }

  static class SuperWriter {

    private final PrintWriter writer;

    public SuperWriter(OutputStream outputStream) {
      writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }

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

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

    public void printLine(String line) {
      writer.println(line);
      if (IN_DEBUG) {
        writer.flush();
      }
    }

    public void printLine(int... vals) {
      if (vals.length == 0) {
        writer.println();
      } else {
        writer.print(vals[0]);
        for (int i = 1; i < vals.length; i++)
          writer.print(" ".concat(String.valueOf(vals[i])));
        writer.println();
      }
      if (IN_DEBUG) {
        writer.flush();
      }
    }

    public void printLine(long... vals) {
      if (vals.length == 0) {
        writer.println();
      } else {
        writer.print(vals[0]);
        for (int i = 1; i < vals.length; i++)
          writer.print(" ".concat(String.valueOf(vals[i])));
        writer.println();
      }
      if (IN_DEBUG) {
        writer.flush();
      }
    }

    public void printLine(double... vals) {
      if (vals.length == 0) {
        writer.println();
      } else {
        writer.print(vals[0]);
        for (int i = 1; i < vals.length; i++)
          writer.print(" ".concat(String.valueOf(vals[i])));
        writer.println();
      }
      if (IN_DEBUG) {
        writer.flush();
      }
    }

    public void printLine(int prec, double... vals) {
      if (vals.length == 0) {
        writer.println();
      } else {
        String precision = "%." + prec + "f";
        writer.print(String.format(precision, vals[0]).replace(',', '.'));
        precision = " " + precision;
        for (int i = 1; i < vals.length; i++)
          writer.print(String.format(precision, vals[i]).replace(',', '.'));
        writer.println();
      }
      if (IN_DEBUG) {
        writer.flush();
      }
    }

    public <E> void printLine(Collection<E> vals) {
      if (vals.size() == 0) {
        writer.println();
      } else {
        int i = 0;
        for (E val : vals) {
          if (i++ == 0) {
            writer.print(val.toString());
          } else {
            writer.print(" ".concat(val.toString()));
          }
        }
        writer.println();
      }
      if (IN_DEBUG) {
        writer.flush();
      }
    }

    public void print(String value) {
      writer.print(value);
      if (IN_DEBUG) {
        writer.flush();
      }
    }
  }

}