with second right up position second left down position second left down position and second right down position according to the position information of the last new chirography coordinate point of the new chirography coordinate lattice in the standard latin letter during the hand writing classify the coarse classification candidate letter aggregation with s 1 2 into the coarse classification candidate letter aggregations with third right up position third left down position third left down position and third right down position according to the position information of the last new chirography coordinate point of the new chirography coordinate lattice in the standard latin letter during the hand writing classify the coarse classification candidate letter aggregation with s 1 3 into the coarse classification candidate letter aggregations with fourth right up position fourth left down position fourth left down position and fourth right down position according to the position information of the last new chirography coordinate point of the new chirography coordinate lattice in the standard latin letter during the hand writing classify the coarse classification candidate letter aggregation with first left up position into the coarse classification candidate letter aggregations with first left arch opening and first non left arch opening according to whether there is left arch opening during the hand writing and take the two coarse classification candidate letter aggregations as the coarse classification candidate letter aggregation that matches with the inputted hand written latin letter classify the coarse classification candidate letter aggregation with first left down position first right up position and first right down into.