FPTP, SNTV, and simple closed-list PR systems are easiest to count, as only one vote total figure for each party or candidate is required to work out the results. The BV and LV systems require the polling officials to count a number of votes on a single ballot paper, and Parallel and MMP systems often require the counting of two ballot papers. AV, BC, and STV, as preferential systems requiring numbers to be marked on the ballot, are more complex to count.