/in/ex2.c: In function 'main':
/in/ex2.c:9:17: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'char **' [-Wformat=]
     scanf ("%d %s",&month,firstday);
                 ^
/in/ex2.c:16:23: warning: passing argument 1 of 'whatday' from incompatible pointer type [-Wincompatible-pointer-types]
     int First=whatday(firstday);
                       ^~~~~~~~
/in/ex2.c:5:5: note: expected 'char *' but argument is of type 'char **'
 int whatday(char* firstday);
     ^~~~~~~
/in/ex2.c:11:10: warning: unused variable 'weekday' [-Wunused-variable]
     char*weekday[7]={"Sun","Mon","Tue","Wed","Thu","Fri","Sat",};
          ^~~~~~~