#include <cstdio>
#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int a = (b); (a) <= (c); ++(a))
#define nR(a,b,c) for(register int a = (b); (a) >= (c); --(a))
#define Fill(a,b) memset(a, b, sizeof(a))
#define Max(a,b) ((a) > (b) ? (a) : (b))
#define Min(a,b) ((a) < (b) ? (a) : (b))
#define Swap(a,b) ((a) ^= (b) ^= (a) ^= (b))
#define ON_DEBUGG
#ifdef ON_DEBUGG
#define D_e_Line printf("\n----------\n")
#define D_e(x) cout << (#x) << " : " << x << endl
#define Pause() system("pause")
#define FileOpen() freopen("in.txt", "r", stdin)
#else
#define D_e_Line ;
#define D_e(x) ;
#define Pause() ;
#define FileOpen() ;
#endif
using namespace std;
struct ios{
template<typename ATP>inline ios& operator >> (ATP &x){
x = 0; int f = 1; char ch;
for(ch = getchar(); ch < '0' || ch > '9'; ch = getchar()) if(ch == '-') f = -1;
while(ch >= '0' && ch <= '9') x = x * 10 + (ch ^ '0'), ch = getchar();
x *= f;
return *this;
}
}io;
#define int long long
inline int Gcd(int a, int b){
while(b ^= a ^= b ^= a %= b);
return a;
// if(!b) return a;
// return Gcd(b, a % b);
}
inline void Exgcd(int a, int b, int &x, int &y){
if(!b)
x = 1, y = 0;
else
Exgcd(b, a % b, y, x), y -= x * (a / b);
}
#undef int
int main(){
#define int long long
int a, b, m, n, L;
io >> a >> b >> m >> n >> L;
int A = n - m, B = L, C = a - b;
if(A < 0){
A = -A, C = -C;
}
int r = Gcd(A, B);
if(C % r){
printf("Impossible");
return 0;
}
A /= r, B /= r, C /= r;
//D_e(B);
int x, y;
Exgcd(A, B, x, y);
// cout << x * C << endl;
// cout << x * C % B << endl;
// cout << x * C % B + B << endl;
printf("%lld", (x * C % B + B) % B);
return 0;
}
/*
(n - m) * x + L * y = a - b
A = n - m
B = L
C = A - B
*/
