{"trustable":true,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cp\u003eYou are given a tree (an undirected connected acyclic graph) consisting of $$$n$$$ vertices and $$$n - 1$$$ edges. A number is written on each edge, each number is either $$$0$$$ (let\u0027s call such edges $$$0$$$-edges) or $$$1$$$ (those are $$$1$$$-edges).\u003c/p\u003e\u003cp\u003eLet\u0027s call an ordered pair of vertices $$$(x, y)$$$ ($$$x \\ne y$$$) \u003cspan class\u003d\"tex-font-style-bf\"\u003evalid\u003c/span\u003e if, while traversing the simple path from $$$x$$$ to $$$y$$$, we never go through a $$$0$$$-edge after going through a $$$1$$$-edge. Your task is to calculate the number of \u003cspan class\u003d\"tex-font-style-bf\"\u003evalid\u003c/span\u003e pairs in the tree.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first line contains one integer $$$n$$$ ($$$2 \\le n \\le 200000$$$) — the number of vertices in the tree.\u003c/p\u003e\u003cp\u003eThen $$$n - 1$$$ lines follow, each denoting an edge of the tree. Each edge is represented by three integers $$$x_i$$$, $$$y_i$$$ and $$$c_i$$$ ($$$1 \\le x_i, y_i \\le n$$$, $$$0 \\le c_i \\le 1$$$, $$$x_i \\ne y_i$$$) — the vertices connected by this edge and the number written on it, respectively.\u003c/p\u003e\u003cp\u003eIt is guaranteed that the given edges form a tree.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003ePrint one integer — the number of \u003cspan class\u003d\"tex-font-style-bf\"\u003evalid\u003c/span\u003e pairs of vertices.\u003c/p\u003e"}},{"title":"Examples","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e7\n2 1 1\n3 2 0\n4 2 1\n5 2 0\n6 7 1\n7 2 1\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e34\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Note","value":{"format":"HTML","content":"\u003cp\u003eThe picture corresponding to the first example:\u003c/p\u003e\u003cp\u003e\u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/98fc6b40f055d1311a609ee5f5b5c8a5?v\u003d1714250122\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e\u003c/p\u003e"}}]}