public class Hello{
public static void Main(){
char[] lines = System.Console.ReadLine().ToString().ToCharArray();
for(char moji='A'; moji<='Z'; ++moji) {
if ( moji >= lines[0] && moji <= lines[lines.Length - 1]) {
System.Console.WriteLine(moji);
}
}
}
}
public class Hello{
public static void Main(){
char[] lines = System.Console.ReadLine().ToString().ToCharArray();
for(char moji='A'; moji<='Z'; ++moji) {
if (moji.Equals(lines[0])) {
System.Console.WriteLine("true");
break;
} else if (moji.Equals(lines[lines.Length - 1])) {
System.Console.WriteLine("false");
break;
}
}
}