A platform team rolls a new build out to a fleet of n servers, numbered 1 through n in rollout order. Once a server exhibits the regression, every server rolled out after it exhibits it too — the fault only ever gets worse as the rollout proceeds, never better — so the fleet's health record (one flag per server, 0 for healthy and 1 for regressed) is guaranteed to look like a block of 0s followed by a block of 1s. At least one server in the fleet is regressed. Given the full health record, find the number of the very first server that is regressed.

Input format

• Line 1: an integer n — the number of servers.
• Line 2: n integers, each 0 or 1 — the health flags for servers 1 through n, in order. The sequence is guaranteed non-decreasing, and the last flag is guaranteed to be 1.

Output format

Print a single integer: the smallest 1-indexed server number whose flag is 1.

Constraints

• 1 <= n <= 200000
• Each flag is 0 or 1.
• The flags are non-decreasing (all 0s precede all 1s).
• At least one flag is 1 (equivalently, the last flag is 1).

5
0 0 1 1 1

3

1
1

1