> #include <stdio.h>
> 
> __int64 e_gcd(__int64 a, __int64 b, __int64 *x, __int64 *y)
> {
> 	__int64 x1, y1, p;
> 	if (b == 0)
> 	{
> 		*x = 1;
> 		*y = 0;
> 		return a;
> 	}
> 
> 	p = e_gcd(b, a % b, &x1, &y1);
> 
> 	*x = y1;
> 	*y = x1 - (a / b) * y1;
> 	return p;
> }
> 
> __int64 abs(__int64 a)
> {
> 	return (a > 0) ? a : -a;
> }
> 
> int main()
> {
> 	__int64 x, y, m, n, L;
> 	__int64 a, b, t, r, gcdans, lcmans, ans;
> 
> 	while (scanf("%I64d %I64d %I64d %I64d %I64d", &x, &y, &m, &n, &L) != -1)
> 	{
> 		x %= L;
> 		y %= L;
> 		m %= L;
> 		n %= L;
> 
> 		if (x > y)
> 		{
> 			a = x - y;
> 			b = (n - m + L) % L;
> 		}
> 		else
> 		{
> 			a = y - x;
> 			b = (m - n + L) % L;
> 		}
> 		
> 		gcdans = e_gcd(a, L, &t, &r);
> 		lcmans = a / gcdans * L;
> 		if (b % gcdans != 0)
> 		{
> 			printf("Impossible\n");
> 		}
> 		else
> 		{
> 			ans = (b / gcdans * t + lcmans) % lcmans;
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~这个地方也错了
> 			printf("%I64d\n", ans);
> 		}
> 	}
> 	return 0;
> }