foo.c: In function 'main':
foo.c:5:27: warning: unused variable 'd' [-Wunused-variable]
    5 |     int m1,m2,d1,d2,a,b,c,d;
      |                           ^
foo.c:5:25: warning: unused variable 'c' [-Wunused-variable]
    5 |     int m1,m2,d1,d2,a,b,c,d;
      |                         ^
foo.c:37:22: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
   37 |         printf("%d",b-a-1);
      |                     ~^~
foo.c:37:22: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]

[Hydro](https://hydro.ac)提供评测服务