根据用户输入的百分制成绩，统计出学生成绩的分布状况.60分以下为F，60分为E，60~70分为D，70~80分为C，80~90为B，90~100为A。-Based on user input percentile scores, statistics of the distribution of student achievement of .60 points or less, F, 60 into E, 60 ~ 70 into D, 70 ~ 80 is divided into C, 80 ~ 90 to B, 90 ~ 100 to A.