因为你的score变量加的是count变量，而count变量每次循环加1，所以你的程序实际的运行过程是：

第一次循环：score = 53 + 0 = 53；    count = 0 + 1 = 1;

第二次循环：score = 53 + 1 = 54；    count = 1 + 1 = 2;

第三次循环：score = 54 + 2 = 56；    count = 2 + 1 = 3;

第四次循环：score = 56 + 3 = 59；    count = 3 + 1 = 4;

第五次循环：score = 59 + 4 = 63；    count = 4 + 1 = 5;

跳出循环