(a, b) = map(int, input().split(' '))
(c, d) = map(int, input().split(' '))
first_b = b
first_d = d
pick_d = 0
pick_b = 0
not_pick_b = 0
not_pick_d = 0
if b == d:
print(b)
else:
while True:
if (b - first_d) % c == 0 and b - first_d != 0 and (b - first_d) // c > 0:
pick_b += 1
break
else:
if b > 10000:
not_pick_b += 1
break
b += a
while True:
if (d - first_b) % a == 0 and (d - first_b)!= 0 and (d - first_b) // a > 0:
pick_d += 1
break
else:
if d > 10000:
not_pick_d += 1
break
d += c
if pick_b == pick_d == 1:
print(min(b, d))
if not_pick_b == not_pick_d == 1:
print('-1')#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "
#define rep(i,a,b) for(int i = (a); i <= (b); i++)
#define repa(i,a,b) for(int i = (a); i >= (b); i--)
#define pll pair<lli,lli>
#define pb push_back
#define MAX 100
lli a,b,c,d,dif;
map<lli,lli> mapa;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> a >> b >> c >> d;
dif = d-b;
while (true) {
if (mapa[dif] == 1) {
b = -1;
break;
}
mapa[dif] = 1;
if (dif == 0) break;
if (dif < 0) {
dif += c;
d += c;
}
else if (dif > 0) {
dif -= a;
b += a;
}
}
cout << b;
return 0;
}
762C - Two strings | 802M - April Fools' Problem (easy) |
577B - Modulo Sum | 1555B - Two Tables |
1686A - Everything Everywhere All But One | 1469B - Red and Blue |
1257B - Magic Stick | 18C - Stripe |
1203B - Equal Rectangles | 1536A - Omkar and Bad Story |
1509A - Average Height | 1506C - Double-ended Strings |
340A - The Wall | 377A - Maze |
500A - New Year Transportation | 908D - New Year and Arbitrary Arrangement |
199A - Hexadecimal's theorem | 519C - A and B and Team Training |
631A - Interview | 961B - Lecture Sleep |
522A - Reposts | 1166D - Cute Sequences |
1176A - Divide it | 1527A - And Then There Were K |
1618E - Singers' Tour | 1560B - Who's Opposite |
182B - Vasya's Calendar | 934A - A Compatible Pair |
1618F - Reverse | 1684C - Column Swapping |