foo.cc: In function 'int bfs(int)':
foo.cc:23:21: warning: statement has no effect [-Wunused-value]
   23 |         { v[now.x+1]==1;
      |           ~~~~~~~~~~^~~
foo.cc:28:20: warning: statement has no effect [-Wunused-value]
   28 |         {v[now.x-1]==1;
      |          ~~~~~~~~~~^~~
foo.cc:34:23: warning: statement has no effect [-Wunused-value]
   34 |             v[now.x*2]==1;
      |             ~~~~~~~~~~^~~
foo.cc: In function 'int main()':
foo.cc:44:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   44 | scanf("%d%d",&n,&k);
      | ~~~~~^~~~~~~~~~~~~~

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