10. A company structures its production process in two sequential phases. 5,000 units were sold, with 3,000 units of the finished product at the beginning of the year and 2,000 units at the end of the year. In the first phase, 5,000 units began to be manufactured, and there were 1,000 units in progress at the beginning. and 3,000 units in progress at the end of the period, while in the second phase the initial production in progress was 700 units and the production in progress final 500 units. Of semi-finished products, at the beginning, there were 2,000 units. If in all cases the input-output ratio is 1 to 1, how many units were started during the period in phase 2?