#include <cstdio>
#include <cstdlib>
#include <cstring>

using namespace std;

/*
x=c%y
x+ay=c;
x+ay=c;
c-ay=x;
c-ay=x;

*/
int main(){
	//int n;scanf("%d",&n);
	long long a1,a2,a3,b1,b2,b3,c;
	int a,b;
	scanf("%d%d",&a,&b);a1=a,b1=b;
	scanf("%d%d",&a,&b);a2=a,b2=b;
	scanf("%d%d",&a,&b);a3=a,b3=b;
	
	long long y1=b1*b2,x1=a1*b2,y2=b1*b2,x2=a2*b1;
	long long c1=(a2-a1),c2=(a3-a2);
	long long ya=b1,yb=b2;
	long long y11;while(y11=yb%ya){yb=ya,ya=y11;}
	y11=ya;
	ya=b2,yb=b3;
	long long y22;while(y22=yb%ya){yb=ya,ya=y22;}
	y22=ya;
	if(c1%y11||c2%y22){
		printf("-1\n");return 0; 
	}
	for(long long xx=0;xx<=y11;xx+=a1){
		if((c1-xx)%y2==0){
			long long yy=(c1-xx)/y2;
			if(yy<=0){
				printf("-1\n");
				return 0;
			}
			printf("%lld\n",x1+xx);
		}
	}
	
	return 0; 
}