{"trustable":true,"prependHtml":"\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$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003eMr. Chopsticks is interested in random phenomena, and he conducts an experiment to study randomness. In the experiment, he throws n balls into m boxes in such a manner that each ball has equal probability of going to each boxes. After the experiment, he calculated the statistical variance V as\u003cbr\u003e $$V\u003d\\frac{\\sum_{i\u003d1}^{m}(X_{i}-\\bar X)^{2}}{m}$$\u003cbr\u003ewhere $X_{i}$ is the number of balls in the ith box, and $\\bar X$ is the average number of balls in a box.\u003cbr\u003eYour task is to find out the expected value of V.\u003cbr\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"The input contains multiple test cases. Each case contains two integers n and m (1 \u0026lt;\u003d n, m \u0026lt;\u003d 1000 000 000) in a line.\u003cbr\u003eThe input is terminated by n \u003d m \u003d 0.\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"For each case, output the result as A/B in a line, where A/B should be an irreducible fraction. Let B\u003d1 if the result is an integer."}},{"title":"Sample","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\u003e2 1\r\n2 2\r\n0 0\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e0/1\r\n1/2\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Hint","value":{"format":"HTML","content":"\u003cbr\u003eIn the second sample, there are four possible outcomes, two outcomes with V \u003d 0 and two outcomes with V \u003d 1.\u003cbr\u003e"}}]}