###### Category

###### Similar Problems

## 0773. Elevator

###### Time limit : 1000 ms

Memory limit : 64 mb

Edward works as an engineer for Non-trivial Elevators: Engineering, Research and Construction (NEERC). His new task is to design a brand new elevator for a skyscraper with h floors.

Edward has an id´ee fixe: he thinks that four buttons are enough to control the movement of the elevator.

His last proposal suggests the following four buttons:

• Move *a* floors up.

• Move *b* floors up.

• Move *c* floors up.

• Return to the first floor.

Initially, the elevator
is on the first floor. A passenger uses the first three buttons to reach the
floor she needs. If a passenger tries to move *a*, *b* or *c* floors up and there is no such floor
(she attempts to move higher than the *h*-th floor), the elevator doesn’t move.

To prove his plan worthy, Edward wants to know how many floors are actually accessible from the first floor via his elevator. Help him calculate this number.

Input

The first line of the
input file contains one integer h — the height of the skyscraper (1 ≤ *h* ≤ 500 000).

The second line contains
three integers a, b and c — the parameters of the buttons (1 ≤ *a*, *b*,
*c* ≤ 100 000).

Output

Output one integer number — the number of floors that are reachable from the first floor.

Samples

№ |
Input |
Output |

1 |
15 4 7 9 |
9 |

Text from: Uzbekistan subregional