/in/foo.c: In function 'main':
/in/foo.c:18:24: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
  if( ((w==11||l==11)&&(abs(w-l)>=2)) || ((w>11||l>11)&&(abs(w-l)==2)))
                        ^~~
/in/foo.c:4:21: warning: unused variable 'flag' [-Wunused-variable]
     int i=0,j=0,u,t,flag=0,w=0,l=0;
                     ^~~~
/in/foo.c:4:19: warning: unused variable 't' [-Wunused-variable]
     int i=0,j=0,u,t,flag=0,w=0,l=0;
                   ^
/in/foo.c:4:17: warning: unused variable 'u' [-Wunused-variable]
     int i=0,j=0,u,t,flag=0,w=0,l=0;
                 ^