76.
Use this Azumarill set:
Azumarill @ Leftovers
Ability: Huge Power
Adamant Nature
-> Substitute
-> Focus Punch
-> Waterfall
-> Bounce
Azumarill will force plenty of switches allowing you to sub, and then you can waterfall on all his things, Focus Punch if he happens to have Ferrothorn and bounce if he happens to have Mega Venusaur