Output the number of different ways the driver can choose the motels to make the trip, under the given constraints.

Sample Input 1

1
500
0

Sample Output 1

0

Sample Input 2

970
1030
0

Sample Output 2

1

Sample Input 3

970
1040
0

Sample Output 3

4

Sample Input 4

970
1030
1
4960

Sample Output 4

2