(1)at+bp=c有解的条件是c%gcd(a,b)=0;
#include <stdio.h>
long long x1,y1;
long long extended(long long a,long long b)
{
long long gcd;
if(b==0)
{
x1=1;
y1=0;
return a;
}
gcd=extended(b,a%b);
long long t=x1;
x1=y1;
y1=t-(a/b)*y1;
return gcd;
}
int main()
{
long long x,y,m,n,l;
while(scanf("%I64d%I64d%I64d%I64d%I64d",&x,&y,&m,&n,&l)!=-1)
{
if(n==m)
{
printf("Impossible\n");
continue;
}
x=(x-y)%l;
m=(n-m)%l;
long long gcd=extended(m,l);
if(x%gcd!=0)
{
printf("Impossible\n");
continue;
}
x1=x1*(x/gcd);
l/=gcd;
printf("%I64d\n",(x1%l+l)%l);
}
return 0;
}