MB4 235a: Participating in the Eruv Chatzeros (369:1); Which Houses Count Towards Obligating Towards an Eruv (370:1)

Giving money to a baker so that when the baker sells the bread for an eruv chatzerot he acquires a share in the eruv (מעות אינם קונות).

Participating in the eruv chatzerot by contributing one's own bread.

All residents must participate in order for an eruv chatzerot to work. What type of dwelling obligates the resident to participate in the eruv?