Index: lib/dataStructure/segmentTree.cpp
==================================================================
--- lib/dataStructure/segmentTree.cpp
+++ lib/dataStructure/segmentTree.cpp
@@ -1,10 +1,11 @@
 //-------------------------------------------------------------
 // Segment tree
 //   in some general form
 //
 // Verified by
+//   - Codeforces 698 B (bug fixed)
 //   - Codeforces 200 D
 //   - Codeforces 107 C (old version)
 //   - Codeforces 104 E (old version)
 //-------------------------------------------------------------
 
@@ -103,10 +104,12 @@
 		}
 	}
 
 	void CalcMidNode(int lv, int idx)
 	{
+		ResolveLazy(lv-1, idx*2);
+		ResolveLazy(lv-1, idx*2+1);
 		tree[lv][idx] = Node::Concat(tree[lv-1][idx*2], tree[lv-1][idx*2+1]);
 	}
 
 	void ResolveLazy(int lv, int idx)
 	{