P4895 Snow Fishing Alone on a Cold River

Given an unrooted tree, find the number of essentially different independent sets in it.

The first line contains an integer $n$, the number of nodes in the tree ($n \leq 5\times 10^5$). Lines $2$ to $n$ each contain two integers $u$ and $v$, indicating that there is an edge connecting $u$ and $v$.

Output a single integer: the number of valid ways modulo $10^9+7$.

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