Statement

After yet another fight with his girlfriend, William knows very well that there is only one way to be forgiven: bring her a bouquet of fresh edelweiss flowers, her favourites. These flowers can be easily found in the mountains where William lives, however, you are not allowed to pick them unless you have a special permit. But there's no time for bureaucracy after such a fight, so he gotta take the risk and pick them without it! Unfortunately, after picking up the very first flower, he triggered an unexpected alarm! By quickly hacking the alarm control unit, William realised that the warning is going to be transmitted to the forestry police by a line of N directional antennas in the mountains. Each antenna has a receiver with a threshold level of L_i decibel, and is able to transmit to following antennas with a power of P_i decibels. The signal decreases in strength by D decibel while travelling the distance between any two consecutive antennas...