/in/foo.cc: In function 'int main()':
/in/foo.cc:143:18: error: 'n' was not declared in this scope
     scanf("%d", &n);
                  ^
/in/foo.cc:147:20: error: 'read' was not declared in this scope
         int u=read(),v=read();
                    ^
/in/foo.cc:148:15: error: 'v' was not declared in this scope
         ins(u,v);
               ^
/in/foo.cc:152:12: error: 'read' was not declared in this scope
     n=read();
            ^
/in/foo.cc:157:37: error: 'z' was not declared in this scope
             printf("%d ",solvemax(y,z));
                                     ^
/in/foo.cc:161:27: error: 'z' was not declared in this scope
             solvechange(y,z,x);
                           ^