
ZOJ Problem Set  4085
Little Sub loves math very much. He enjoys counting numbers. One day, Mr.Potato gives him an interesting math problem. Please help Little Sub solve this problem. Let's sort the integers $1, 2, \dots, N$ according to alphabetical order. For example, when $N=11$, the order should be: $1,10,11,2,3,4,5,6,7,8,9$. We define $Q(N, K)$ as the position of number $K$ in the sorted $N$ numbers. For example, $Q(11, 2)=4$. Given $K$ and $M$, please find the smallest $N$ such that $Q(N, K) = M$. InputThere are multiple test cases. The first line of the input contains an integer $T$ ($1 \le T \le 100$), indicating the number of test cases. For each test case: The first and only line contains two integers $K$ and $M$ ($1 \le K \le 10^8$, $1 \le M \le 10^8$). OutputFor each test case, please output the answer in one line. If there is no such $N$, please output "0" (without quotes). Sample Input2 2 4 10000001 100000000 Sample Output11 1000000088888880 Author: ZHANG, Zhihuan Source: ZOJ Monthly, January 2019 