Problem:


Score : 100 points

Problem Statement

Three poles stand evenly spaced along a line. Their heights are a, b and c meters, from left to right.
We will call the arrangement of the poles beautiful if the tops of the poles lie on the same line, that is, b-a = c-b.

Determine whether the arrangement of the poles is beautiful.

Constraints

1 \leq a,b,c \leq 100

a, b and c are integers.

Input

Input is given from Standard Input in the following format:

a b c

Output

Print YES if the arrangement of the poles is beautiful; print NO otherwise.

Sample Input 1

2 4 6

Sample Output 1

YES

Since 4-2 = 6-4, this arrangement of poles is beautiful.

Sample Input 2

2 5 6

Sample Output 2

NO

Since 5-2 \neq 6-5, this arrangement of poles is not beautiful.

Sample Input 3

3 2 1

Sample Output 3

YES

Since 1-2 = 2-3, this arrangement of poles is beautiful.



Sample input:
2 4 6


Sample output:
YES

Submission status: Accepted

Solution code:
###
### atcorder test program
###

import sys

### math class
class math:
    ### pi
    pi = 3.14159265358979323846264338

    ### GCD
    def gcd(self, a, b):
        if b == 0:
            return a
        return self.gcd(b, a%b)

    ### LCM
    def lcm(self, a, b):
        return (a*b)//self.gcd(a,b)

    ### Prime number search
    def Pnum(self, a):
        if a == 1: return False
        for i in range(2,int(a**0.5)+1):
            if a % i == 0:
                return False
        return True

    ### Circle area
    def caria(self, r):
        return r*r*self.pi

math = math()

### output class
class output:
    ### list
    def list(self, l):
        l = list(l)
        print(" ", end="")
        for i, num in enumerate(l):
            print(num, end="")
            if i != len(l)-1:
                print(" ", end="")
        print()

output = output()

### input sample
#i = input()
#A, B, C = [x for x in input().split()]
#inlist = [int(w) for w in input().split()]
#R = float(input())
#A = [int(x) for x in input().split()]
#for line in sys.stdin.readlines():
#    x, y = [int(temp) for temp in line.split()]

### output sample
#print("{0} {1} {2:.5f}".format(A//B, A%B, A/B))
#print("{0:.6f} {1:.6f}".format(R*R*math.pi,R*2*math.pi))
#print(" {}".format(i), end="")

A, B, C = [int(x) for x in input().split()]

if B-A == C-B:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

ans = "YES" if a-b == b-c else "NO"

print(ans)

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if b-a==c-b:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-
a,b,c = [int(i) for i in input().split()]
if 1 <= a and b and c <= 100:
    if b - a == c - b:
        print("YES")
    else:
        print("NO")

Submission status: Accepted

Solution code:
a,b,c=sorted(map(int, input().split()))
print("YES" if b-a==c-b else "NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

s = b - a
t = c - b

if s == t:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
if (b - a) == (c - b):
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c =[int(i) for i in input().split()]
if b-a == c-b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if b-a==c-b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
print((lambda a,b,c:"YNEOS"[a-2*b+c!=0::2])(*map(int,input().split())))

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print(['NO','YES'][(a-b)==(b-c)])

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
print('YES') if a+c == b*2 else print('NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
print('YES'if b-a == c-b else 'NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().rstrip().split(' '))

if b-a == c-b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if (b - a) == (c - b):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print('YES' if b*2==a+c else 'NO')

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print('YES' if  b-a==c-b else 'NO')

Submission status: Accepted

Solution code:
a = list(map(int, input().split()))
if a[1]-a[0]==a[2]-a[1]:
	print('YES')
else:
	print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
ans = "YES" if b - a == c - b else "NO"
print(ans)

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if a+c==2*b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
#A-ι⊥l
a,b,c = map(int,input().split())
print('YES' if a-b==b-c else 'NO')

Submission status: Accepted

Solution code:

def read_input():
    a, b, c = map(int, input().split())
    return a, b, c


def submit():
    a, b, c = read_input()

    if b - a == c - b:
        print('YES')
    else:
        print('NO')


if __name__ == '__main__':
    submit()

Submission status: Accepted

Solution code:
a = list(map(int,input().split()))
if a[0] - a[1] == a[1] - a[2]:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = [int(n) for n in input().split()]

if b -a == c - b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if(a-b==b-c):
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split()); print("YES" if b - a == c - b else "NO");

Submission status: Accepted

Solution code:
import sys
a,b,c = list(map(int, input().split()))
print("YES" if b*2 == a+c else "NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if b - a == c -b:
    print('YES')
elif a - b == b -c:
    peint('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if b-a == c-b:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

print(["NO", "YES"] [b - a == c - b])

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-

a, b, c = map(int, input().split())

print('YES' if 2*b == a+c else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

if b-a == c-b:
    ans = 'YES'
else:
    ans = 'NO'

print(ans)

Submission status: Accepted

Solution code:
A,B,C=map(int,input().split(" "))
print("YES" if B-A==C-B else "NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print(["NO","YES"][(b-a)==(c-b)])

Submission status: Accepted

Solution code:
# ABC058A - ι⊥l
a, b, c = list(map(int, input().rstrip().split()))
print("YES" if b - a == c - b else "NO")

Submission status: Accepted

Solution code:
import functools

import os

INF = float('inf')


def inp():
    return int(input())


def inpf():
    return float(input())


def inps():
    return input()


def inl():
    return list(map(int, input().split()))


def inlf():
    return list(map(float, input().split()))


def inls():
    return input().split()


def inpm(line):
    return [inp() for _ in range(line)]


def inpfm(line):
    return [inpf() for _ in range(line)]


def inpsm(line):
    return [inps() for _ in range(line)]


def inlm(line):
    return [inl() for _ in range(line)]


def inlfm(line):
    return [inlf() for _ in range(line)]


def inlsm(line):
    return [inls() for _ in range(line)]


def debug(fn):
    if not os.getenv('LOCAL'):
        return fn

    @functools.wraps(fn)
    def wrapper(*args, **kwargs):
        print('DEBUG: {}({}) -> '.format(
            fn.__name__,
            ', '.join(
                list(map(str, args)) +
                ['{}={}'.format(k, str(v)) for k, v in kwargs.items()]
            )
        ), end='')
        ret = fn(*args, **kwargs)
        print(ret)
        return ret

    return wrapper

a, b, c = inl()
print('YES' if b-a == c-b else 'NO')

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
ans='NO'
if b-a==c-b:
  ans='YES'
print(ans)

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
n = b - a
m = c - b
if n == m:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c=map(int, input().split())

if b-a==c-b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
x = list(map(int, input().split()))

if (x[1] - x[0]) == (x[2] - x[1]):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
import sys, os

f = lambda:list(map(int,input().split()))
if 'local' in os.environ :
    sys.stdin = open('./input.txt', 'r')

def solve():
    a,b,c = f()
    if b-a == c -b:
        print('YES')
    else:
        print('NO')

solve()

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())

if (b - a) == (c - b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
A, B, C = map(int,input().split())
if B-A == C-B:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a = list(map(int,input().split()))
if (a[0]-a[1])==(a[1]-a[2]):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
print('YES' if b - a == c - b else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
x = b - a
y = c - b
if x == y:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = [int(item) for item in input().split()]
if b - a == c - b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if b - a == c - b:
	print("YES")
else:
	print("NO")

Submission status: Accepted

Solution code:
a,b,c  =map(int, input().split())

if c-b == b-a:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
from functools import reduce
import math

def main():
    # N! を求める
    # f = math.factorial(N)
    
    # 切り捨て
    # 4 // 3
    # 切り上げ
    #-(-4 // 3)
    
    # 初期値用:十分大きい数(100億)
    # 1e10

    # 初期値用:十分小さい数(-100億)
    # -1e10
    
    # 1文字のみを読み込み
    # 入力:2
    # a = input().rstrip()
    # 変数:a='2'
    
    # スペース区切りで標準入力を配列として読み込み
    # 入力:2 4 5 7
    # a, b, c, d = (int(_) for _ in input().split())  
    # 変数:a=2 b=4 c=5 d =7
    
    # 1文字ずつ標準入力を配列として読み込み
    # 入力:2 4 5 7
    # a = list(int(_) for _ in input().split())
    # 変数:a = [2, 4, 5, 7]    

    # 1文字ずつ標準入力を配列として読み込み
    # 入力:2457
    # a = list(int(_) for _ in input())
    # 変数:a = [2, 4, 5, 7]    
    a, b, c = (int(_) for _ in input().split())
    if b-a == c-b:
        print('YES')
    else:
        print('NO')
    
if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
A,B,C = map(int, input().split())
if B-A == C-B:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
import sys

def main():
    input = sys.stdin.readline
    A = list(map(int, input().split()))

    if A[1] - A[0] == A[2] - A[1]:
        return 'YES'
    else:
        return 'NO'


if __name__ == '__main__':
    print(main())

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if (b - a == c - b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
d = b - a
e = c - b
if (d == e):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
#coding utf-8 -*-

lis=list(map(int,input().split()))
lis_1=sorted(lis)

if lis_1[2] - lis_1[1] == lis_1[1] - lis_1[0]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
if b-a == c-b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if a - b == b - c:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

if b-a==c-b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())
if (b-a) == (c-b):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
def INSTR():
	return input()

def INNUM():
	return int(INSTR())

def INSTR_S():
	return INSTR().split()

def INNUM_S():
	return map(int, INSTR_S())

def INSTR_SM(n):
	return [tuple(INSTR_S()) for _ in range(n)]

def INNUM_SM(n):
	return [tuple(INNUM_S()) for _ in range(n)]

A, B, C = INNUM_S()
print("YNEOS"[(B-A)!=(C-B)::2])

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-

a,b,c = map(int,input().split())

if b- a == c - b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print("YNEOS"[a-b!=b-c::2])

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print('YES' if(b-a)==(c-b) else 'NO')

Submission status: Accepted

Solution code:
def lll(a: int, b: int, c: int)->bool:
    return c-b == b-a


if __name__ == "__main__":
    a, b, c = map(int, input().split())
    yes = lll(a, b, c)
    print('YES' if yes else 'NO')

Submission status: Accepted

Solution code:
a = [ int(i) for i in input().split() ]
if a[1] - a[0] == a[2] - a[1]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
#!usr/bin/env python3
from collections import defaultdict
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return list(map(int, sys.stdin.readline().split()))
def I(): return int(sys.stdin.readline())
def LS():return list(map(list, sys.stdin.readline().split()))
def S(): return list(sys.stdin.readline())[:-1]
def IR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = I()
    return l
def LIR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = LI()
    return l
def SR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = S()
    return l
def LSR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = SR()
    return l
mod = 1000000007

#A
a,b,c = LI()
if b-a == c-b:
    print("YES")
else:
    print("NO")
#B

#C
"""
n = I()
s = SR(n)
for i in range(n):
    for j in range(len(s[i])):
        while s[i][j] in s[i][:j]:
            s[i][j] = "0"+s[i][j]
ans = set(s[0])
for i in range(1,n):
    ans &= set(s[i])
ans = sorted(list(ans))
if len(ans) == 0:print()
else:
    for i in range(len(ans)):
        ans[i] = ans[i][-1]
    ans.sort()
    for i in range(len(ans)-1):
        print(ans[i],end = "")
    print(ans[-1])
"""

#D
"""
n,m = LI()
ln = [n-1]
lm = [m-1]
a = n-1
b = m-1
while a > 2:
    a -= 2
    ln.append(ln[-1]+a)
while b > 2:
    b -= 2
    lm.append(lm[-1]+b)
la = len(ln)
lb = len(lm)
for i in range(la):
    if i or a == 2:
        ln.append(ln[la-i-1])
for i in range(lb):
    if i or b == 2:
        lm.append(lm[lb-i-1])
x,y = LIR(2)
lx = 0
ly = 0
for i in range(n-1):
    lx += ln[i]*(x[i+1]-x[i])%mod
    lx %= mod
for i in range(m-1):
    ly += lm[i]*(y[i+1]-y[i])%mod
    ly %= mod
ans = lx*ly%mod
print(ans)
"""
#E

#F

#G

#H

#I

#J

#K

#L

#M

#N

#O

#P

#Q

#R

#S

#T

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print("YES"if b-a==c-b else "NO")

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-

a, b, c = map(int, input().split())

if b - a == c - b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a, b, c = list(map(int, input().split()))

if b-a==c-b:
	print('YES')
else:
	print('NO')

Submission status: Accepted

Solution code:
a=[int(i) for i in input().split()]
a.sort()
print('YES' if a[2]-a[1]==a[1]-a[0] else 'NO')

Submission status: Accepted

Solution code:
[a,b,c] = list(map(int, input().split()))
if b-a == c-b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split());print('YNEOS'[a-2*b+c!=0::2])

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if a+c==2*b:print("YES")
else:print("NO")

Submission status: Accepted

Solution code:
a,b,c = [int(x) for x in input().split()]
if(b-a == c-b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = list(map(int, input().split()))

if b-a == c-b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-
a, b, c = map(int, input().split())
if b - a == c - b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
ans = "NO"
if(b-a == c-b):
  ans = "YES"
print(ans)

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

ans = 'NO'
if b - a == c - b:
    ans = 'YES'

print(ans)

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if b-a==c-b:
    print('YES')
else:
    print(('NO'))

Submission status: Accepted

Solution code:
# coding: utf-8
a, b, c = map(int, input().split())
print('YES' if (b - a) == (c - b) else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if a-b == b-c:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if(b - a == c - b):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if a+c==b*2:print("YES")
else:print("NO")

Submission status: Accepted

Solution code:
a, b, c = (int(i) for i in input().split())
if b-a==c-b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
def main():
    a, b, c = map(int, input().split())
    if b-a == c-b:
        print("YES")
    else:
        print("NO")


if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
#58
a, b, c = map(int, input().split())
if(2*b == a+c):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split(' '))
if a+c==2*b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if b-a==c-b:
    print('YES')
else:print('NO')

Submission status: Accepted

Solution code:
a,b,c=(int(x) for x in input().split())

if b-a==c-b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if a-b == b-c:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
A,B,C=map(int,input().split())
if B-A == C-B:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a=list(map(int,input().split()))
if a[1]-a[0] == a[2]-a[1]:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a, b, c = list(map(int, input().split()))
if ((b-a) == (c-b)):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a=[int(i) for i in input().split()]
if a[2]-a[1]==a[1]-a[0]:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if (b - a) == (c - b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

if(b - a == c - b):
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c=[int(i) for i in input().split()]
print("YES" if b-a==c-b else "NO")

Submission status: Accepted

Solution code:
from sys import stdin
a, b, c = [int(x) for x in stdin.readline().rstrip().split()]
if (b-a) == (c-b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if( (b-a)==(c-b) ):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
#!/usr/bin/python3
# ABC058_A
"""
ι⊥l（柱）
"""

def beautiful():
    """
    本体
    """
    a, b, c = map(int, input().split())
    if b-a == c-b:
        print('YES')
    else:
        print('NO')


def main():
    beautiful()


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
# coding: utf-8
a, b, c = map(int, input().split())
print(['NO', 'YES'][b - a == c - b])

Submission status: Accepted

Solution code:
A,B,C=map(int,input().split())
if C-B==B-A:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
# ABC 058 A - ι⊥l
a,b,c =map(int,input().split())
if 2*b == a+c:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c=map(int, input().split())
print('YES' if b-a == c-b else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if b - a == c -b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split());print('YES' if a+c==2*b else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
if(b-a == c-b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = [ int(x) for x in input().split() ]

ans =  (b - a) == (c - b)

print("YES" if ans else "NO")
print()

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
print('YES' if (a - b) == (b - c) else 'NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())

if b-a == c-b :
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,raw_input().split())
print["NO","YES"][b-a==c-b]

Submission status: Accepted

Solution code:
a,b,c=input().split()
if int(b)-int(a)==int(c)-int(b):
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
abc = list(map(int, input().split()))

if abc[1]-abc[0]==abc[2]-abc[1]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if a-b==b-c:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())
if a+c==b*2:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
if b*2==a+c:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
if b - a == c - b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())

print("YES" if b-a == c-b else "NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())

if(b-a==c-b):
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())
if (b-a) == (c-b):
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if b-a == c-b:
    ans = "YES"
else:
    ans = "NO"
print(ans)

Submission status: Accepted

Solution code:
a,b,c = list(map(int, input().split()))
if 2*b == a+c:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print('YES' if(b-a==c-b) else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print('YES' if (b - a) == (c - b) else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print("YES" if b-a == c-b else "NO")

Submission status: Accepted

Solution code:
""" AtCoder """

a, b, c = map(int, input().split())

if b - a == c - b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print('YES') if b-a == c-b else print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if (b-a) == (c-b):
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print('YES' if (b-a)==(c-b) else 'NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())

print('YES' if b-a == c-b else 'NO')

Submission status: Accepted

Solution code:
A, B, C = [int(_) for _ in input().split()]

if B - A == C - B:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = [int(x) for x in input().split()]
if b-a == c-b: print('YES')
else: print('NO')

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())
if b-a==c-b:
	print('YES')
else:
	print('NO')

Submission status: Accepted

Solution code:
a,b,c = (int(i) for i in input().split())  
if b-a == c-b :
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = [int(x) for x in input().split()]

print('YES' if b - a == c -b else 'NO')

Submission status: Accepted

Solution code:
A,B,C = map(int,input().split())
print("YES" if B-A==C-B else "NO")

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())
if c - b == b - a:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if c-b == b-a:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
x=input().split()
if int(x[0]) + int(x[2]) == int(x[1]) * 2:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = [int(i) for i in input().split()]

if (b-a == c-b) :
	print("YES")
else :
	print("NO")

Submission status: Accepted

Solution code:
A,B,C = map(int,input().split())
if B-A == C-B: print("YES")
else: print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print("YES") if (b-a) == (c-b) else print("NO")

Submission status: Accepted

Solution code:
int_a, int_b, int_c = map(int, input().split())

if (int_b - int_a) == (int_c - int_b):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print('YES' if a+c==2*b else 'NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if 2 * b == a + c:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
if b - a == c - b:
	print('YES')
else:
	print('NO')

Submission status: Accepted

Solution code:
def abc058_a():
    a, b, c = map(int, input().split())
    if (b - a) == (c - b):
        print("YES")
    else:
        print("NO")


abc058_a()

Submission status: Accepted

Solution code:
a ,b,c= map(int, input().split())
if b - a == c-b:
    print("YES")
else:print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())


if(b-a == c-b):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = (int(x) for x in input().split())
if b - a == c - b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
s=input().split()
if(int(s[0])-int(s[1])==int(s[1])-int(s[2])):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
if (a+c)/2 == b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
l = b - a
r = c - b
if(l == r):
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
def main():
    a, b, c = map(int, input().split())
    if b - a == c - b:
        print('YES')
    else:
        print('NO')


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
a, b, c = [int(i) for i in input().split() ]
print("YES" if 2*b == a+c else "NO")

Submission status: Accepted

Solution code:
a, b, c = [int(i) for i in input().split()]
if b - a == c - b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
abc=list(map(int,input().split()))
abc.sort(reverse=True)
if abc[0]-abc[1]==abc[1]-abc[2]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
from statistics import mean, median,variance,stdev
import sys
import math

x = input().split()
#y = input().split()
a = []
for i in range(len(x)):
   a.append(int(x[i]))
if a[2]-a[1]==a[1]-a[0]:print("YES")
else : print("NO")

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-
a,b,c = map(int,input().split())
if b-a == c-b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-


def main():
    """Function."""
    a, b, c = map(int, input().split())

    if b - a  == c - b:
        print("YES")
    else:
        print("NO")


if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())
print(['NO','YES'][b-a==c-b])

Submission status: Accepted

Solution code:
#横にn個入力
a, b, c = map(int, input().split())
if b - a == c - b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = [int(_) for _ in input().split()]
if b-a == c-b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c = [int(x) for x in input().split()]
print('YES') if b-a == c-b else print('NO')

Submission status: Accepted

Solution code:
a=list(map(int,input().split()))
if a[1]-a[0] == a[2]-a[1]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a, b, c = list(map(int, input().split()))

if b - a == c - b:
	print('YES')
else:
	print('NO')

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split())
ans = 'NO'
if b - a == c - b:
	ans = 'YES'
print(ans)

Submission status: Accepted

Solution code:
t = list(map(int, input().rstrip().split()))

print('YES' if (t[1] - t[0] == t[2] - t[1]) else 'NO')

Submission status: Accepted

Solution code:
a=input().strip().split(" ")

b=[int(i) for i in a]

if(b[1]-b[0]==b[2]-b[1]):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a = list(map(int,input().split()))
if (a[0] - a[1]) == (a[1] - a[2]):
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split());print('YNEOS'[b-a!=c-b::2])

Submission status: Accepted

Solution code:
a, b, c = map(int, raw_input().split())
print "YES" if b - a == c - b else "NO"

Submission status: Accepted

Solution code:
a,b,c = map(int,input().split(" "))
if b - a == c - b:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
if 2 * b == a + c:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a, b , c = map(int, input().split())
print('YES' if b - a == c - b else 'NO')

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
a,b,c = map(int, input().split())

if b-a==c-b:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
a, b, c = (int(i) for i in input().split())

if b - a ==  c - b:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
num = list(map(int, input().split()))
if num[1]-num[0] == num[2]-num[1]:
	print('YES')
else:
	print('NO')

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())

if b - a == c - b:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a,b,c = map(int, input().split())
if c-b == b-a:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a, b, c = map(int, input().split())
print('YNEOS'[2*b!=a+c::2])

Submission status: Accepted

Solution code:
a, b, c = map(int,input().split())
if (a-b)==(b-c) or (b-a)==(c-b):
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
a,b,c=map(int,input().split())

if b-a == c-b:
    print("YES")
else:
    print("NO")