/in/foo.cc: In function 'void DFS1(int, int)':
/in/foo.cc:52:3: error: 'Siz' was not declared in this scope
   Siz[x]+=Siz[y];
   ^~~
/in/foo.cc: In function 'int LCA(int, int)':
/in/foo.cc:64:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(i=0;i<=18;i++)
  ^~~
/in/foo.cc:66:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   if(x==y) return x;
   ^~
/in/foo.cc:67:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(i=18;i>=0;i--)
  ^~~
/in/foo.cc:71:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   if(x==y) return x;
   ^~
/in/foo.cc: In function 'int UP(int, int)':
/in/foo.cc:76:8: warning: unused variable 'k' [-Wunused-variable]
  int i,k;
        ^
/in/foo.cc: In function 'void Solve2(int, int, int)':
/in/foo.cc:104:8: warning: unused variable 'k' [-Wunused-variable]
  int i,k,j;
        ^
/in/foo.cc:104:10: warning: unused variable 'j' [-Wunused-variable]
  int i,k,j;
          ^
/in/foo.cc: In function 'void CAL(int)':
/in/foo.cc:121:8: warning: unused variable 'p' [-Wunused-variable]
  int i,p,j;
        ^
/in/foo.cc: In function 'void ST()':
/in/foo.cc:131:10: warning: unused variable 'p' [-Wunused-variable]
  int i,j,p;
          ^