/in/foo.cc: In function 'void solve()':
/in/foo.cc:32:21: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int u = rec[d][S];
                     ^
/in/foo.cc:59:20: note: 'id' was declared here
     int ans = INF, id;
                    ^~