/in/foo.cc: In function 'void init()':
/in/foo.cc:10:59: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   10 |             else f[i][j] = max(f[i][j - 1], f[i + (1 << j - 1)][j - 1]);
      |                                                         ~~^~~