/in/foo.cc: In function 'int main()':
/in/foo.cc:16:21: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  for(int i=1;i+(1<<j-1)<=n;i++)
                    ~^~
/in/foo.cc:17:43: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
      Sam[i][j]=max(Sam[i][j-1],Sam[i+(1<<j-1)][j-1]);
                                          ~^~