I need to check if the user input is using the correct delimiters. However the code I have right now would still allow for example "15-10/1999", which it shouldn't. I'm not quite sure how exactly to change the while condition to disallow this though. 

```
char delim1, delim2;
do { 
    printf("Please enter date (dd-mm-yy or dd/mm/yy):");   
    scanf("%d%c%d%c%d", &day1, &delim1,  &mon1, &delim2, &year1);
} while (delim1 != '-' && delim1 != '/' && delim2 != '-' && delim2 != '/');

```