/in/foo.cc: In function 'int dfs(int, int, int)':
/in/foo.cc:83:48: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(f = dfs(vj, ed, min(fl, cap[i] - flow[i])))
                                                ^
/in/foo.cc: In function 'void dfs1(int, int)':
/in/foo.cc:99:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < to1[now].size(); i++)
                 ~~^~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void dfs2(int, int)':
/in/foo.cc:110:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < to2[now].size(); i++)
                 ~~^~~~~~~~~~~~~~~~~