/in/foo.cc: In function 'void dfs(int, int, int)':
/in/foo.cc:15:17: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  dfs(u-1,x-(1<<u-1),y+(1<<u-1));
                ~^~
/in/foo.cc:15:28: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  dfs(u-1,x-(1<<u-1),y+(1<<u-1));
                           ~^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:22:22: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   for(int j=1;j<=1<<n+1;j++)
                     ~^~
/in/foo.cc:26:22: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   for(int j=1;j<=1<<n+1;j++){
                     ~^~