#include<stdio.h>
void main()
{
 long int x,y,m,n,L;
   scanf("%ld%ld%ld%ld%ld",&x,&y,&m,&n,&L);
  if(m>n)
  {
	  if((x-y>0)&&(L+y-x)%(m-n)==0)
		  printf("%ld\n",(L+y-x)/(m-n));
	  
		 else
			 if(x-y<0&&(y-x)%(m-n)==0)
            printf("%ld\n",(y-x)/(m-n));
		  else
			  printf("Impossible\n");
  }

	 else
		 if(m<n)
	  {
		  if(x-y>0&&(x-y)%(n-m)==0)
			  printf("%ld\n",(x-y)/(n-m));
		 
			 else
				 if((x-y)<0&&(L+x-y)%(n-m)==0)
				  printf("%ld\n",(L+x-y)/(n-m));
			  else
                  printf("Impossible\n");
	  }
}