foo.cpp:11:15: error: 'b' has not been declared
 int max(int a,b)
               ^
foo.cpp: In function 'int max(int, int)':
foo.cpp:13:10: error: 'b' was not declared in this scope
     if(a>b)
          ^
foo.cpp:15:12: error: 'b' was not declared in this scope
     return b;
            ^
foo.cpp: In function 'int mian()':
foo.cpp:36:13: warning: unused variable 'machine' [-Wunused-variable]
         int machine=way[which][step];
             ^
foo.cpp: In function 'int max(int, int)':
foo.cpp:16:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^