/in/foo.cc: In function 'void Read()':
/in/foo.cc:35:28: warning: iteration 19 invokes undefined behavior [-Waggressive-loop-optimizations]
  for(i=1;i<=LogN;i++)Pow[i]=Pow[i-1]<<1;
                      ~~~~~~^~~~~~~~~~~~
/in/foo.cc:35:11: note: within this loop
  for(i=1;i<=LogN;i++)Pow[i]=Pow[i-1]<<1;
           ^