void checkNum(char c) {
if (isalnum(c)) {
printf("%c is alphanumeric\n", c);
} else {
printf("%c is not alphanumeric\n", c);
}
}
int main() {
char char1 = 'B';
char char2 = 'X';
char char3 = '+';
checkNum(char1);
checkNum(char2);
checkNum(char3);
return 0;
}