A coastal survey team maintains a straight-line chain of n signal beacons, numbered 1 to n from the shore outward, each holding a stored charge level. The team powers on beacons strictly in order from beacon 1 to beacon n. When a beacon is powered on, it activates (and is counted) only if its current charge is strictly greater than 0. Every time a beacon activates, the shared feeder cable immediately draws exactly 1 unit of charge from every beacon that comes after it in the chain, never dropping any beacon's charge below 0. Beacons that fail to activate draw no charge from anyone. Determine how many beacons end up activated once the whole chain has been powered on in order.

Input format

The first line contains a single integer n, the number of beacons. The second line contains n space-separated integers p_1, p_2, ..., p_n, the initial charge level of each beacon in chain order.

Output format

Print a single integer: the number of beacons that activate.

Constraints

• 1 <= n <= 100
• 0 <= p_i <= 100

5
1 1 2 1 3

3

3
0 1 2

2