Simplified diagram of a zigzag strategy by a weekly organized deconfinement. Here we have chosen Monday and Thursday as days of deconfinement. The other days of the week are lockdown days. Schematically, deconfinement amounts to a changeof lane, which can go up to the intermediate lane (because only two days per week are deconfined). The relaxed lane is excluded (or forbidden). When the number of days of deconfinement increases, the intermediate lane may become excluded as well.