#include<iostream>
__int64 Ext_Euclid(__int64 a,__int64 b,__int64* x,__int64* y)
{
	__int64 p,q,d;
	if(a==0){*x=0;*y=1;return b;}
	if(b==0){*x=1;*y=0;return a;}
	d=Ext_Euclid(b,a%b,&p,&q);
	*x=q;
	*y=p-(a/b)*q;
	return d;
}
int main()
{
	/*freopen("1.IN","r",stdin);
	freopen("my.OUT","w",stdout);*/
	__int64 x,y,m,n,l;//x为A的起始点,y为B的起始点
	//m为x的步长，n为y的步长，l为纬度长
	__int64 c,a,d;
	__int64 p,q;
	while(scanf("%I64d%I64d%I64d%I64d%I64d",&x,&y,&m,&n,&l)!=EOF){
	if(n==m)printf("Impossible\n");
	else {
		if(m>n){a=m-n;c=y-x;}
		else {a=n-m;c=x-y;}
		d=Ext_Euclid(a,l,&p,&q);
		if((x>y?(x-y):(y-x))%d)printf("Impossible\n");
		else {
			p*=c/d;
			while(p<0)p+=l;
			printf("%I64d\n",p);
		}
	}}
	return 0;
}