Petya loves lucky numbers. Everybody knows that lucky numbers are positive integers whose decimal representation contains only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.

Petya has a number consisting of $*n*$ digits without leading zeroes. He represented it as an array of digits without leading zeroes. Let's call it $*d*$. The numeration starts with $1$, starting from the most significant digit. Petya wants to perform the following operation $*k*$ times: find the minimum $*x*$ $(1 ≤ *x* < *n*)$ such that $*d*_{*x*} = 4$ and $*d*_{*x* + 1} = 7$, if $*x*$ is odd, then to assign $*d*_{*x*} = *d*_{*x* + 1} = 4$, otherwise to assign $*d*_{*x*} = *d*_{*x* + 1} = 7$. Note that if no $*x*$ was found, then the operation counts as completed and the array doesn't change at all.

You are given the initial number as an array of digits and the number $*k*$. Help Petya find the result of completing $*k*$ operations.

Input

The first line contains two integers $*n*$ and $*k*$ $(1 ≤ *n* ≤ 10^{5}, 0 ≤ *k* ≤ 10^{9})$ — the number of digits in the number and the number of completed operations. The second line contains $*n*$ digits without spaces representing the array of digits $*d*$, starting with $*d*_{1}$. It is guaranteed that the first digit of the number does not equal zero.

Output

In the single line print the result without spaces — the number after the $*k*$ operations are fulfilled.

Note

In the first sample the number changes in the following sequence: $4727447 → 4427447 → 4427477 → 4427447 → 4427477$.

In the second sample: $4478 → 4778 → 4478$.