/in/foo.c: In function 'main':
/in/foo.c:7:15: warning: unused variable 'b' [-Wunused-variable]
     int i,a,j,b,l,flag;
               ^
/in/foo.c:7:11: warning: unused variable 'a' [-Wunused-variable]
     int i,a,j,b,l,flag;
           ^