#include <stdio.h>
main (){
    char s[20], b[30];
    printf("Enter your name: ");
    fgets(s, 20, stdin);
    if (s[strlen(s)-1] == \n) s[strlen(s)-1] = '\0';
    snprintf(b, 30, "Hello, %s.\n", s);
    fputs(b, stdout);
}