if2.c

  #include <stdio.h>

  int main()
  {
     int age;
     printf("Acme movie theatre\n");
     printf("Input your age: ");
     scanf("%d", &age);
     if (age < 21)
     {
         printf("You are too young to watch this movie.\n");
     } else
     {
         printf("You are old enough to watch this movie.\n");
     }
     return 0;
  }