/in/foo.cc: In function 'void solve()':
/in/foo.cc:30:16: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int u=rec[d][S];
                ^
/in/foo.cc:57:14: note: 'id' was declared here
  int ans=INF,id;
              ^~