View Compilation Error

0_0_25729263_19455.cpp: In function 'int ask(int, int, int, int)':
0_0_25729263_19455.cpp:36:9: error: declaration of 'int lca' shadows a parameter
     int lca=GetLCA(x,y),ans=0,res=v[lca]^z;
         ^
0_0_25729263_19455.cpp:36:23: error: 'GetLCA' was not declared in this scope
     int lca=GetLCA(x,y),ans=0,res=v[lca]^z;
                       ^
0_0_25729263_19455.cpp:40:61: error: 'ans' was not declared in this scope
         if(vis[ch[x][d]]+vis[ch[y][d]]-2*vis[ch[lca][d]]>0) ans|=1<<i;
                                                             ^
0_0_25729263_19455.cpp:46:16: error: 'ans' was not declared in this scope
     return max(ans,res);
                ^
0_0_25729263_19455.cpp:46:20: error: 'res' was not declared in this scope
     return max(ans,res);
                    ^
0_0_25729263_19455.cpp: In function 'int main()':
0_0_25729263_19455.cpp:93:30: error: too few arguments to function 'int ask(int, int, int, int)'
             int ans=ask(x,y,z);
                              ^
0_0_25729263_19455.cpp:35:5: note: declared here
 int ask(int x,int y,int z,int lca){
     ^