View Compilation Error

0_0_33897162_31456.cpp: In function 'void work()':
0_0_33897162_31456.cpp:47:17: error: 'hd' was not declared in this scope
         if(edge[hd.end].size()) Q.push({i, edge[i][0].first, 0, edge[i][0].second});
                 ^