#include <stdio.h>
#include <ctype.h>
int main()
{
    char ch;
    printf("Enter a character: ");
    scanf("%c", &ch);
    if (isalnum(ch))
    {
        printf("%c is an alphanumeric character.\n", ch);
    }
    else
    {
        printf("%c is not an alphanumeric character.\n", ch);
    }
    return 0;
}