#include <bits/stdc++.h>typedef long long ll;
const int N = 1e5 + 5;int main() {int a, b, c;scanf ("%d%d%d", &a, &b, &c);bool flag = true;if (c == 0) {if (a == b) {flag = true;} else {flag = false;}} else {int d = (b - a) / c;if (d >= 0 && (b - a) % c == 0) {flag = true;} else {flag = false;}}if (flag) {puts ("YES");} else {puts ("NO");}return 0;
}

#include <bits/stdc++.h>typedef long long ll;
const int N = 1e5 + 5;int main() {int n, a, b, c, d;scanf ("%d%d%d%d%d", &n, &a, &b, &c, &d);int d1 = a - d, d2 = b - c, d3 = a + b - c - d;int l = 1, r = n;l = std::max (l, 1 - d1);r = std::min (r, n - d1);l = std::max (l, 1 - d2);r = std::min (r, n - d2);l = std::max (l, 1 - d3);r = std::min (r, n - d3);if (l <= r) {long long ans = 1ll * (r - l + 1) * n;std::cout << ans << '\n';} else {puts ("0");}return 0;
}

#include <bits/stdc++.h>int main() {std::ios::sync_with_stdio (false);std::cin.tie (0);std::map<long long, int> mp;int n;std::cin >> n;long long sum = 0;int mx = 0;for (int i=0; i<n; ++i) {int x;std::cin >> x;sum += x;mp[sum]++;mx = std::max (mx, mp[sum]);}std::cout << n - mx << '\n';return 0;
}

#include <bits/stdc++.h>const int N = 1e5 + 5;
std::set<int> st;
std::map<int, int> left, right;int main() {int n, x;scanf ("%d", &n);scanf ("%d", &x);st.insert (x);int ans;for (int i=0; i<n-1; ++i) {scanf ("%d", &x);auto it = st.lower_bound (x);if (it != st.end () && left.count (*it) == 0) {left[*it] = x;ans = *it;} else {--it;right[*it] = x;ans = *it;}st.insert (x);printf ("%d ", ans);}return 0;
}

#include <bits/stdc++.h>const int N = 1e5 + 5;
int a[N];
long long dp[N];
std::pair<int, int> mx[N][20];
int n;void init_ST() {for (int i=0; i<n; ++i) {mx[i][0] = {a[i], i};}for (int j=1; (1<<j)<=n; ++j) {for (int i=0; i+(1<<j)-1<n; ++i) {mx[i][j] = std::max (mx[i][j-1], mx[i+(1<<(j-1))][j-1]);}}
}int query_max(int l, int r) {int k = 0; while (1<<(k+1) <= r - l + 1) k++;return std::max (mx[l][k], mx[r-(1<<k)+1][k]).second;
}int main() {scanf ("%d", &n);a[n-1] = n - 1;for (int i=0; i<n-1; ++i) {scanf ("%d", a+i);a[i]--;}init_ST ();long long ans = 0;dp[n-1] = 0;for (int i=n-2; i>=0; --i) {int p = query_max (i + 1, a[i]);dp[i] = dp[p] - (a[i] - p) + n - i - 1;ans += dp[i];}printf ("%I64d\n", ans);return 0;
}