/in/foo.cc: In function 'int build(int)':
/in/foo.cc:18:7: warning: unused variable 'c' [-Wunused-variable]
   int c=a[y][i];
       ^
/in/foo.cc:24:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int move(int, int)':
/in/foo.cc:29:7: warning: unused variable 'c' [-Wunused-variable]
   int c=f[x][i];
       ^
/in/foo.cc: In function 'int add(int, int)':
/in/foo.cc:47:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int move(int, int)':
/in/foo.cc:42:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^