Codeforces Round 373 (Div. 1)
A
Efim and Strange Grade
Codeforces
1700
原题
←C →
翻译中…

Efim just received his grade for the last test. He studies in a special school and his grade can be equal to any positive decimal fraction. First he got disappointed, as he expected a way more pleasant result. Then, he developed a tricky plan. Each second, he can ask his teacher to round the grade at any place after the decimal point (also, he can ask to round to the nearest integer).

翻译中…

There are $*t*$ seconds left till the end of the break, so Efim has to act fast. Help him find what is the maximum grade he can get in no more than $*t*$ seconds. Note, that he can choose to not use all $*t*$ seconds. Moreover, he can even choose to not round the grade at all.

翻译中…

In this problem, classic rounding rules are used: while rounding number to the $*n*$-th digit one has to take a look at the digit $*n* + 1$. If it is less than $5$ than the $*n*$-th digit remain unchanged while all subsequent digits are replaced with $0$. Otherwise, if the $*n* + 1$ digit is greater or equal to $5$, the digit at the position $*n*$ is increased by $1$ (this might also change some other digits, if this one was equal to $9$) and all subsequent digits are replaced with $0$. At the end, all trailing zeroes are thrown away.

翻译中…

For example, if the number $1.14$ is rounded to the first decimal place, the result is $1.1$, while if we round $1.5$ to the nearest integer, the result is $2$. Rounding number $1.299996121$ in the fifth decimal place will result in number $1.3$.

翻译中…

Input

翻译中…

The first line of the input contains two integers $*n*$ and $*t*$ ($1 ≤ *n* ≤ 200 000$, $1 ≤ *t* ≤ 10^{9}$) — the length of Efim's grade and the number of seconds till the end of the break respectively.

翻译中…

The second line contains the grade itself. It's guaranteed that the grade is a positive number, containing at least one digit after the decimal points, and it's representation doesn't finish with $0$.

翻译中…

Output

翻译中…

Print the maximum grade that Efim can get in $*t*$ seconds. Do not print trailing zeroes.

翻译中…

Note

翻译中…

In the first two samples Efim initially has grade $10.245$.

翻译中…

During the first second Efim can obtain grade $10.25$, and then $10.3$ during the next second. Note, that the answer $10.30$ will be considered incorrect.

翻译中…

In the third sample the optimal strategy is to not perform any rounding at all.

翻译中…

样例

Input #1
6 1
10.245
Output #1
10.25
InputCopy OutputCopy
Input #2
6 2
10.245
Output #2
10.3
InputCopy OutputCopy
Input #3
3 100
9.2
Output #3
9.2
InputCopy OutputCopy
题目信息
题号
718A
时间限制
1 s
内存限制
256 MB
标签
动态规划
模拟
数学

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。