import java.io.*;
import java.lang.reflect.Array;
import java.util.*;
import java.util.concurrent.ThreadLocalRandom;
import java.util.function.*;

import static java.lang.Math.*;
import static java.util.Arrays.*;
//import static java.util.Collections.*;
//import static java.util.Comparator.*;

import java.awt.Point;

class Solver{
  static int infI = (int) 1e9;
  static long infL = (long) 1e18;
  //  static long mod = (int) 1e9 +7;
  static long mod = 998244353;
  static String yes = "Yes";
  static String no = "No";

  Util util = new Util();
  Random rd = ThreadLocalRandom.current();
  MyReader in = new MyReader(System.in);
  MyWriter out = new MyWriter(System.out);
  MyWriter log = new MyWriter(System.err){
    @Override
    protected void ln(){
      super.ln();
      flush();
    };
  };

  char[] S=in.ch();

  Object solve(){ return S[0] == S[1] && S[1] != S[2]; }

  long bSearchL(long o,long n,Predicate<Long> judge){
    for (long c = 0;1 < Math.abs(n -o);)
      if (judge.test(c = o +n >>1))
        o = c;
      else
        n = c;
    return o;
  }

}

class Edge{
  int id;
  int u;
  int v;
  long l;
  Edge rev;

  Edge(int id,int u,int v){
    this.id = id;
    this.u = u;
    this.v = v;
  }

  void rev(Edge rev){ rev.l = l; }

}

class Util{
  long st = System.currentTimeMillis();

  long elapsed(){ return System.currentTimeMillis() -st; }

  static int[][] trans(int[]... T){ return arr(new int[T[0].length][],i -> arrI(T.length,j -> T[j][i])); }

  static int[][] addId(int[][] T){
    return arr(new int[T.length][],i -> {
      int[] t = copyOf(T[i],T[i].length +1);
      t[t.length -1] = i;
      return t;
    });
  }

  static long[][] trans(long[]... T){ return arr(new long[T[0].length][],i -> arrL(T.length,j -> T[j][i])); }

  static double[][] trans(double[]... T){ return arr(new double[T[0].length][],i -> arrD(T.length,j -> T[j][i])); }

  static int[] arrI(int N,IntUnaryOperator f){
    int[] ret = new int[N];
    setAll(ret,f);
    return ret;
  }

  static long[] arrL(int N,IntToLongFunction f){
    long[] ret = new long[N];
    setAll(ret,f);
    return ret;
  }

  static double[] arrD(int N,IntToDoubleFunction f){
    double[] ret = new double[N];
    setAll(ret,f);
    return ret;
  }

  static <T> T[] arr(T[] arr,IntFunction<T> f){
    setAll(arr,f);
    return arr;
  }

}

class MyReader{
  byte[] buf = new byte[1 <<16];
  int ptr = 0;
  int tail = 0;
  InputStream in;

  MyReader(InputStream in){ this.in = in; }

  byte read(){
    if (ptr == tail)
      try {
        tail = in.read(buf);
        ptr = 0;
      } catch (IOException e) {}
    return buf[ptr++];
  }

  boolean isPrintable(byte c){ return 32 < c && c < 127; }

  boolean isNum(byte c){ return 47 < c && c < 58; }

  byte nextPrintable(){
    byte ret = read();
    while (!isPrintable(ret))
      ret = read();
    return ret;
  }

  int it(){ return Math.toIntExact(lg()); }

  int[] it(int N){ return Util.arrI(N,i -> it()); }

  int[][] it(int H,int W){ return Util.arr(new int[H][],i -> it(W)); }

  int idx(){ return it() -1; }

  int[] idx(int N){ return Util.arrI(N,i -> idx()); }

  int[][] idx(int H,int W){ return Util.arr(new int[H][],i -> idx(W)); }

  int[][] qry(int Q){ return Util.arr(new int[Q][],i -> new int[]{idx(), idx(), i}); }

  long lg(){
    byte i = nextPrintable();
    boolean negative = i == 45;
    long n = negative ? 0 : i -'0';
    while (isPrintable(i = read()))
      n = 10 *n +i -'0';
    return negative ? -n : n;
  }

  long[] lg(int N){ return Util.arrL(N,i -> lg()); }

  long[][] lg(int H,int W){ return Util.arr(new long[H][],i -> lg(W)); }

  double dbl(){ return Double.parseDouble(str()); }

  double[] dbl(int N){ return Util.arrD(N,i -> dbl()); }

  double[][] dbl(int H,int W){ return Util.arr(new double[H][],i -> dbl(W)); }

  char[] ch(){ return str().toCharArray(); }

  char[][] ch(int H){ return Util.arr(new char[H][],i -> ch()); }

  String line(){
    StringBuilder sb = new StringBuilder();

    for (byte c;(c = read()) != '\n';)
      sb.append((char) c);
    return sb.toString();
  }

  String str(){
    StringBuilder sb = new StringBuilder();
    sb.append((char) nextPrintable());

    for (byte c;isPrintable(c = read());)
      sb.append((char) c);
    return sb.toString();
  }

  String[] str(int N){ return Util.arr(new String[N],i -> str()); }

  Edge[] e(int N,int M){ return e(N,M,e -> e.l = 1); }

  Edge[] e(int N,int M,Consumer<Edge> f){
    return Util.arr(new Edge[M],i -> {
      Edge e = new Edge(i,idx(),idx());
      f.accept(e);
      return e;
    });
  }

  Edge[][] g(int N,int M,boolean b){ return g(N,b,e(N,M)); }

  Edge[][] g(int N,int M,boolean b,Consumer<Edge> f){ return g(N,b,e(N,M,f)); }

  Edge[][] g(int N,boolean b,Edge[] E){
    int[] c = new int[N];

    for (Edge e:E) {
      c[e.u]++;
      if (!b)
        c[e.v]++;
    }

    Edge[][] g = Util.arr(new Edge[N][],i -> new Edge[c[i]]);

    for (Edge e:E) {

      g[e.u][--c[e.u]] = e;
      if (!b) {
        Edge rev = new Edge(e.id,e.v,e.u);
        e.rev(rev);
        g[e.v][--c[e.v]] = e.rev = rev;
      }
    }
    return g;
  }
}

class MyWriter{
  OutputStream out;
  byte[] buf = new byte[1 <<16];
  byte[] ibuf = new byte[20];
  int tail = 0;

  MyWriter(OutputStream out){ this.out = out; }

  void flush(){
    try {
      out.write(buf,0,tail);
      tail = 0;
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  private void sp(){ write((byte) ' '); }

  protected void ln(){ write((byte) '\n'); }

  private void write(byte b){
    buf[tail++] = b;
    if (tail == buf.length)
      flush();
  }

  private void write(byte[] b,int off,int len){
    for (int i = off;i < off +len;i++)
      write(b[i]);
  }

  private void write(long n){
    if (n < 0) {
      n = -n;
      write((byte) '-');
    }

    int i = ibuf.length;
    do {
      ibuf[--i] = (byte) (n %10 +'0');
      n /= 10;
    } while (n > 0);

    write(ibuf,i,ibuf.length -i);
  }

  private void print(Object obj){
    if (obj instanceof Boolean)
      print((boolean) obj ? Solver.yes : Solver.no);
    else if (obj instanceof Character)
      write((byte) (char) obj);
    else if (obj instanceof Integer)
      write((int) obj);
    else if (obj instanceof Long)
      write((long) obj);
    else if (obj instanceof char[])
      for (char b:(char[]) obj)
        write((byte) b);
    else if (obj instanceof Collection<?>) {
      Iterator<?> itr = ((Collection<?>) obj).iterator();
      while (itr.hasNext()) {
        print(itr.next());
        if (itr.hasNext())
          ln();
      }
    } else if (obj.getClass().isArray()) {
      int l = Array.getLength(obj);
      boolean ln = false;

      if (0 < l) {
        Object a = Array.get(obj,0);
        ln = !(a instanceof char[]) && a.getClass().isArray();
      }
      for (int i = 0;i < l;i++) {
        print(Array.get(obj,i));
        if (i +1 < l)
          if (ln)
            ln();
          else
            sp();
      }
    } else
      for (char b:Objects.toString(obj).toCharArray())
        write((byte) b);
  }

  void println(Object obj){
    if (obj == null)
      return;
    print(obj);
    ln();
  }
}

class Main{
  public static void main(String[] args) throws Exception{
    Solver solver = new Solver();
    Optional.ofNullable(solver.solve()).ifPresent(solver.out::println);
    solver.out.flush();
    solver.log.println(solver.util.elapsed());
  }
}