import java.util.*;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
while(sc.hasNext()){
char c = sc.next().charAt(0);
if(c >= 'a' && c <= 'z'|| c>='A'&& c <= 'Z'){
System.out.println("YES");
}else{
System.out.println("NO");
}
}
}
} #include<stdio.h>
int main()
{
char a;
scanf("%c",&a);
printf("%s",a>=65&&a<=90||a>=97&&a<=122 ? "YES":"NO");
return 0;
} #include <stdio.h>
int main (void)
{
char ch;
scanf("%c", &ch);
if(ch<=112&&97<ch||65<=ch&&ch<=90)//c语言 ASCII码中,A~Z:65-90, a~z:97-122(分别一一对应)。
printf("YES");
else
printf("NO");
return 0;
} #include <stdio.h>
int main() {
char ch;
scanf("%c",&ch);
if(('a'<=ch&&ch<='z')||('A'<=ch&&ch<='Z'))
{
printf("YES\n");
}
else{
printf("NO\n");
}
return 0;
} #include <stdio.h>
int main()
{
int ch = 0;
while((ch = getchar()) != EOF)
{
if((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))
{
printf("YES");
}
else
{
printf("NO");
}
getchar();
}
return 0;
}