PROBLEM E
Trains

Input File Name: E.DAT
Source File Name: E.PAS or E.C or E.CPP

	Two towns T1 and T2 are connected through a double railroad.The distance 
between T1 and T2 is d meters. From T1 to T2 the trains are leaving every t1 seconds. 
From T2 to T1 the trains are leaving every t2 seconds. The trains from T1 to T2 have a 
speed of v1 m/s. The trains from T2 to T1 have a speed of v2 m/s.

	Your task is to write a program that computes the number of train "rendezvous" on 
the railroad which links T1 and T2, and which occur during the time interval [0, tf] 
seconds.

	We consider that:
		a) at time 0 two trains are leaving (from T1 to T2, and  from T2 to T1);
		b) the input and output data are integers.

	Input:
	Your program reads data sets, one per line, in the following format:

d  v1  v2  t1  t2  tf.

	Output:
	The program writes to the output the number of  "rendezvous".

	Example 
	For the input file:

10  5  5  1  1  2

	the output is:

6