1109

 1 #include<stdio.h>  
 2 #include<math.h>  
 3 int main()  
 4 {  
 5     int a,num;  
 6     while(scanf("%d",&a)!=EOF)  
 7     {  
 8         num=a/10;  
 9         if(a<0||a>100)  
10             num=(-1);  
11     
12         switch(num)  
13         {  
14         case 10:  
15         case 9:printf("A\n");break;  
16         case 8:printf("B\n");break;  
17         case 7:printf("C\n");break;  
18         case 6:printf("D\n");break;  
19         case 5:  
20         case 4:  
21         case 3:  
22         case 2:  
23         case 1:  
24         case 0:printf("E\n");break;  
25         case -1:printf("Score is error!\n");break;  
26         default:break;  
27         }  
28     }  
29 }