import heapq
from itertools import product
from itertools import permutations
import random
import math
import bisect
import sys
from collections import defaultdict
from itertools import combinations


inf = 1 << 60


def exit():
    sys.exit()


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


def II():
    return int(input())


def SI():
    return input()


s = SI()
print("Yes" if int(s[0])+int(s[2]) == int(s[1]) else "No")