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 $*n*$ number segments $[*l*_{1}; *r*_{1}]$, $[*l*_{2}; *r*_{2}]$, ..., $[*l*_{*n*}; *r*_{*n*}]$. During one move Petya can take any segment (let it be segment number $*i*$) and replace it with segment $[*l*_{*i*} + 1; *r*_{*i*} + 1]$ or $[*l*_{*i*} - 1; *r*_{*i*} - 1]$. In other words, during one move Petya can shift any segment to the left or to the right by a unit distance. Petya calls a number full if it belongs to each segment. That is, number $*x*$ is full if for any $*i*$ $(1 ≤ *i* ≤ *n*)$ the condition $*l*_{*i*} ≤ *x* ≤ *r*_{*i*}$ is fulfilled.

Petya makes no more than $*k*$ moves. After that he counts the quantity of full lucky numbers. Find the maximal quantity that he can get.

Input

The first line contains two integers $*n*$ and $*k*$ ($1 ≤ *n* ≤ 10^{5}$, $1 ≤ *k* ≤ 10^{18})$ — the number of segments and the maximum number of moves. Next $*n*$ lines contain pairs of integers $*l*_{*i*}$ and $*r*_{*i*}$ $(1 ≤ *l*_{*i*} ≤ *r*_{*i*} ≤ 10^{18})$.

Please do not use the %lld specificator to read or write 64-bit integers in С++. It is preferred to use the %I64d specificator.

Output

Print on the single line the single number — the answer to the problem.

Note

In the first sample Petya shifts the second segment by two units to the left (it turns into $[4; 7]$), after that number $4$ becomes full.

In the second sample Petya shifts the first segment by two units to the right (it turns into $[42; 47]$), and shifts the second segment by three units to the left (it turns into $[44; 71]$), after that numbers $44$ and $47$ become full.