#include <stdio.h>
#include <string.h>

int isValid(char *s);

int main()
{
  char s[81];

  while (fgets(s, sizeof(s), stdin))
  {
    // remove trailing newline from s
    s[strcspn(s, "\n")] = 0;
    printf("%s is %s\n", s, (isValid(s) ? "valid" : "invalid"));
  }

  return 0;
}