{"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\"\u003eRuins is driving a car to participating in a programming contest. As on a very tight schedule, he will drive the car without any slow down, so the speed of the car is non-decrease real number.\u003cbr\u003e\u003cbr\u003eOf course, his speeding caught the attention of the traffic police. Police record $N$ positions of Ruins without time mark, the only thing they know is every position is recorded at an integer time point and Ruins started at $0$.\u003cbr\u003e\u003cbr\u003eNow they want to know the \u003cb\u003eminimum\u003c/b\u003e time that Ruins used to pass the last position.\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"First line contains an integer $T$, which indicates the number of test cases.\u003cbr\u003e\u003cbr\u003eEvery test case begins with an integers $N$, which is the number of the recorded positions.\u003cbr\u003e\u003cbr\u003eThe second line contains $N$ numbers $a_1$, $a_2$, $\\cdots$, $a_N$, indicating the recorded positions.\u003cbr\u003e\u003cbr\u003eLimits\u003cbr\u003e$1 \\leq T \\leq 100$\u003cbr\u003e$1 \\leq N \\leq 10^5$\u003cbr\u003e$0 \u0026lt; ai \\leq 10^9$\u003cbr\u003e$a_i \u0026lt; a_{i+1}$"}},{"title":"Output","value":{"format":"HTML","content":"For every test case, you should output \u003cb\u003e\u0027Case #x: y\u0027\u003c/b\u003e, where \u003cb\u003ex\u003c/b\u003e indicates the case number and counts from \u003cb\u003e1\u003c/b\u003e and \u003cb\u003ey\u003c/b\u003e is the minimum time."}},{"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\u003e1\r\n3\r\n6 11 21\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003eCase #1: 4\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}