An oriented weighted forest is an acyclic weighted digraph in which from each vertex at most one edge goes. The root of vertex v of an oriented weighted forest is a vertex from which no edge goes and which can be reached from vertex v moving along the edges of the weighted oriented forest. We denote the root of vertex v as root ( v ) . The depth of vertex v is the sum of weights of paths passing from the vertex v to its root. Let's denote the depth of the vertex v as depth ( v ) . Let's consider the process of constructing a weighted directed forest. Initially, the forest does not contain vertices. Vertices are added sequentially one by one. Overall, there are n performed operations of adding. The i -th ( i > 0) adding operation is described by a set of numbers ( k , v 1 , x 1 , v 2 , x 2 , ... , v k , x k ) and means that we should add vertex number i and k edges to the graph: an edge from vertex root ( v 1 ) to vertex i with weight depth ( v 1 ) + x 1 , an edge from vertex root ( v 2 ) to vertex i with weight depth ( v 2 ) + x 2 and so on. If k = 0 , then only vertex i is added to the graph, there are no added edges. Your task is like this: given the operations of adding vertices, calculate the sum of the weights of all edges of the forest, resulting after the application of all defined operations, modulo 1000000007 (10 9 + 7) . The first line contains a single integer n (1 ≤ n ≤ 10 5 ) — the number of operations of adding a vertex. Next n lines contain descriptions of the operations, the i -th line contains the description of the operation of adding the i -th vertex in the following format: the first number of a line is an integer k (0 ≤ k ≤ i - 1) , then follow 2 k space-separated integers: v 1 , x 1 , v 2 , x 2 , ... , v k , x k (1 ≤ v j ≤ i - 1, | x j | ≤ 10 9 ) . The operations are given in the order, in which they should be applied to the graph. It is guaranteed that sum k of all operations does not exceed 10 5 , also that applying operations of ad