#include <cstdio>

 #include <cstring>

 #include <algorithm>

 #include <math.h>

 #include <iostream>

 #include <stack>

 #include <set>

 #include <queue>

 #define MAX(a,b) (a) > (b)? (a):(b)

 #define MIN(a,b) (a) < (b)? (a):(b)

 #define mem(a) memset(a,0,sizeof(a))

 #define INF 1000000007

 #define MAXN 20005

 using namespace std;

 __int64 GCD(__int64 a,__int64 b)

 {

     return a%b==?b:GCD(b,a%b);

 }

 void gcd(__int64 a,__int64 b,__int64 &x,__int64 &y)

 {

     if(!b){x=;y=;}

     else{gcd(b,a%b,y,x); y-=x*(a/b);}

 }

 int main()

 {

     __int64 X,Y,M,N,L;

     while(~scanf("%I64d %I64d %I64d %I64d %I64d",&X,&Y,&M,&N,&L))

     {

         __int64 a = (N-M), b = L, c = (X-Y);

         __int64 g = GCD(a,b);

         if(c%g){ printf("Impossible\n"); continue;}

         __int64 x, y;

         gcd(a, b, x, y);

         x*=(c/g);

         if(x>)x%=(b/g);

         else x=x%(b/g)+(b/g);

         printf("%I64d\n",x);

     }

     return ;

 }