A river has checkpoints on left side and checkpoints on the right side. bridges are built connecting checkpoints across the river. Guards needs to be placed on checkpoints, a guard can protect all the bridges on which this checkpoint is present. There can be more than one guard to protect a single bridge.
Find the minimum number of guards required to protect all the bridges over the river.
Input Format:
Output Format:
Print the minimum number of guards required to protect all the bridges over the river.
Constraints:
Place guards on checkpoint and on left side of river to cover all bridges.