/in/foo.cc: In function 'void build_graph()':
/in/foo.cc:75:32: warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]
   75 |                         if ((i + j & 1) == 1) {
      |                              ~~^~~
/in/foo.cc: In function 'bool judge(long long int)':
/in/foo.cc:152:32: warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]
  152 |                         if ((i + j & 1) == 1) init(st, i * m + j, tot - Gmap[i][j]);
      |                              ~~^~~