1 /**************************************************************
 2     Problem: 1477
 3     User: Tunix
 4     Language: C++
 5     Result: Accepted
 6     Time:0 ms
 7     Memory:1272 kb
 8 ****************************************************************/
 9  
10 //BZOJ 1477
11 #include<cstdio>
12 #include<cstring>
13 #include<cstdlib>
14 #include<iostream>
15 #include<algorithm>
16 #define rep(i,n) for(int i=0;i<n;++i)
17 #define F(i,j,n) for(int i=j;i<=n;++i)
18 #define D(i,j,n) for(int i=j;i>=n;--i)
19 using namespace std;
20 int getint(){
21     int v=0,sign=1; char ch=getchar();
22     while(ch<‘0‘||ch>‘9‘){ if (ch==‘-‘) sign=-1; ch=getchar();}
23     while(ch>=‘0‘&&ch<=‘9‘){ v=v*10+ch-‘0‘; ch=getchar();}
24     return v*=sign;
25 }
26 /******************tamplate*********************/
27 typedef long long LL;
28 void exgcd(int a,int b,int &d,LL &x,LL &y){
29     if (!b) { d=a; x=1; y=0; return; }
30     else {exgcd(b,a%b,d,y,x); y-=x*(a/b);}
31 }
32 int main(){
33     int X=getint(), Y=getint(), M=getint(), N=getint(), L=getint();
34     int a=M-N,b=L,c=Y-X,d=0;
35     LL x,y;
36     if (a<0){ a=-a; c=-c; }
37     if (c<0){ c=c+L; }
38     exgcd(a,b,d,x,y);
39     if (c%d || (M==N && X!=Y)) {printf("Impossible\n"); return 0;}
40     x*=c/d;
41     LL T=x*d/b;// T=x/(b/d)
42     x-=T*b/d;
43     if (x<0) x+=b/d;
44     printf("%lld\n",x);
45     return 0;
46 }