{"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\"\u003eTom has a string containing only lowercase letters. He wants to choose a subsequence of the string whose length is $k$ and lexicographical order is the smallest. It\u0027s simple and he solved it with ease.\u003cbr\u003eBut Jerry, who likes to play with Tom, tells him that if he is able to find a lexicographically smallest subsequence satisfying following 26 constraints, he will not cause Tom trouble any more.\u003cbr\u003eThe constraints are: the number of occurrences of the $i$th letter from a to z (indexed from $1$ to $26$) must in $[L_i, R_i]$.\u003cbr\u003eTom gets dizzy, so he asks you for help.\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"The input contains multiple test cases. Process until the end of file.\u003cbr\u003eEach test case starts with a single line containing a string $S(|S|\\le 10^5)$and an integer $k(1\\le k\\le |S|)$.\u003cbr\u003eThen $26$ lines follow, each line two numbers $L_i,R_i(0\\le L_i\\le R_i\\le |S|)$. \u003cbr\u003eIt\u0027s guaranteed that $S$ consists of only lowercase letters, and $\\sum |S|\\le 3\\times 10^5$.\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"Output the answer string.\u003cbr\u003eIf it doesn\u0027t exist, output $-1$."}},{"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\u003eaaabbb 3\r\n0 3\r\n2 3\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\r\n0 0\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003eabb\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}