in the three other provinces. The Commission on Elections apportions the number of Sanggunian members among the SP districts into which the province is divided. As much as possible, the members are equally divided among the legislative districts. If such equal division is impossible the remaining numbers are assigned to the districts with a bigger population count than the others. The COMELEC likewise factors out the population of independent cities which do not elect provincial officials in determining the apportionment of the Sanggunian members among the districts. Provinces comprising a single congressional district are divided into two sanggunian districts by the COMELEC for purposes of electing SP members. A majority of Sangguniang Panlalawigan districts are contiguous to existing congressional districts. The exceptions are the following: Provinces which comprise a lone congressional district are divided into two Sanggunian districts by the COMELEC. Independent cities which are not allowed to participate in provincial politics are factored out of the congressional districts that contain them: Angeles from Pampanga—1st, Butuan from Agusan del Norte—1st, Cotabato City from Maguindanao—1st, Dagupan from Pangasinan—4th, Naga from Camarines Sur—3rd, Ormoc from 4th, Puerto Princesa from Palawan—3rd, Santiago from Isabela—4th, and Tacloban from Leyte—1st The 4th SP district of Bulacan encompasses the entire 4th Congressional district of Bulacan plus the city of San Jose del Monte, which in 2004 started to elect its own congressional representative but was not separated by law to constitute its own Sangguniang Panlalawigan district. The 1st SP district of Laguna encompasses the entire 1st Congressional district of Laguna plus the city of Biñan, which in 2016 started to elect its own congressional representative but was not separated by law to constitute its own Sangguniang Panlalawigan district. In 2022, the city of Santa Rosa will start to elect its own congressional representative, but would not be separated by law to constitute its own Sangguniang Panlalawigan district. This left out San Pedro as the only remaining city in the 1st congressional district, but the 1st SP district still contains all three cities. The 2nd SP district of Laguna encompasses the entire 2nd Congressional district of Laguna plus the city of Calamba, which in 2019 started to elect its own congressional representative but was not separated by law to constitute its own Sangguniang Panlalawigan district. The 1st and 2nd Congressional districts of Antipolo also serve de facto as SP districts of Rizal, with each being allocated one