View Compilation Error

0_0_25960001_29299.cpp: In function 'int main()':
0_0_25960001_29299.cpp:29:20: error: 'z' was not declared in this scope
      if(x!=y)fa[y]=z,dis[y]=ad(c+dis[a]-dis[b]);
                    ^
0_0_25960001_29299.cpp:30:34: error: lvalue required as increment operand
      else if(ad(dis[b]-dis[a]!=c)++ans;
                                  ^
0_0_25960001_29299.cpp:30:36: error: expected ')' before 'ans'
      else if(ad(dis[b]-dis[a]!=c)++ans;
                                    ^