/in/foo.cc: In function 'int main()':
/in/foo.cc:64:20: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
         w = 1 << k + 1;
                  ~~^~~
/in/foo.cc:72:46: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
             bel[i] = (i < w ? i : bel[i >> k + 1]);
                                            ~~^~~