/in/foo.cc: In function 'int main()':
/in/foo.cc:53:33: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
      if (f[i][j-1].sum<f[i+(1<<j-1)][j-1].sum) f[i][j]=f[i][j-1];
                                ~^~
/in/foo.cc:54:30: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
        else f[i][j]=f[i+(1<<j-1)][j-1];
                             ~^~