Problem:
Score : 300 points

Problem Statement

Given any integer x, Aoki can do the operation below.

Operation: Replace x with the absolute difference of x and K.

You are given the initial value of an integer N. Find the minimum possible value taken by N after Aoki does the operation zero or more times.

Constraints

0 ≤ N ≤ 10^{18}

1 ≤ K ≤ 10^{18}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N K

Output

Print the minimum possible value taken by N after Aoki does the operation zero or more times.

Sample Input 1

7 4

Sample Output 1

1

Initially, N=7.

After one operation, N becomes |7-4| = 3.

After two operations, N becomes |3-4| = 1, which is the minimum value taken by N.

Sample Input 2

2 6

Sample Output 2

2

N=2 after zero operations is the minimum.

Sample Input 3

1000000000000000000 1

Sample Output 3

0

Solution in Python (3.4.3) (judge verdict: Runtime Error)

k=int(input())

a=[]
i=1
d=0
while True:
    if len(str(i))==1:
        a.append(i)
    elif len(str(i))==2:
        I=str(i)
        c=abs(int(I[0])-int(I[1]))
        if c<=1:
            a.append(i)   
            
    elif len(str(i))==3:
        I=str(i)
        for j in range(2):
            c=abs(int(I[j])-int(I[j+1]))
            if c<=1:
                d=d+1
        if d==2:
            a.append(i)
        d=0
        
    elif len(str(i))==4:
        I=str(i)
        for j in range(3):
            c=abs(int(I[j])-int(I[j+1]))
            if c<=1:
                d=d+1
        if d==3:
            a.append(i) 
        d=0
        
    elif len(str(i))==5:
        I=str(i)
        for j in range(4):
            c=abs(int(I[j])-int(I[j+1]))
            if c<=1:
                d=d+1
        if d==4:
            a.append(i)   
        d=0
        
    elif len(str(i))==6:
        I=str(i)
        for j in range(5):
            c=abs(int(I[j])-int(I[j+1]))
            if c<=1:
                d=d+1
        if d==5:
            a.append(i)
        d=0
    
    elif len(str(i))==7:
        I=str(i)
        for j in range(6):
            c=abs(int(I[j])-int(I[j+1]))
            if c<=1:
                d=d+1
        if d==6:
            a.append(i)
            
        d=0    
        
    elif len(str(i))==8:
        I=str(i)
        for j in range(7):
            c=abs(int(I[j])-int(I[j+1]))
            if c<=1:
                d=d+1
        if d==7:
            a.append(i)
            
        d=0    
        
    i=i+1
    if i==10000000:
        break

print(a[k-1])