10.11
#include
int main(){
/* int a,b;
scanf("%*6d%4d%*8d %*6d%4d%*8d",&a,&b);
if(a>b)
printf("%d",a-b);
else
printf("%d",b-a);*/
/* int m,n,r;
scanf("%d%d",&m,&n);
r=m%n;
while(r!=0)
{m=n;
n=r;
r=m%n;
}
printf("%d",n);*/
/* int m,n,r,d;
scanf("%d%d%d",&m,&n,&r);
if(m>n){
d=m;
}
if(m d=n;
}
if(d>r){
printf("%d",d);
}
if(d printf("%d",r);
}*/
/* char s1[10],s2[10];
gets(s1);
gets(s2);
printf("{\"%s\" is \'%s\'}",s2,s1);*/
int a;
scanf("%d",&a);
if(90<=a&&a<=100)
printf("A");
else if(80<=a&&a<90)
printf("B");
else if(70<=a&&a<80)
printf("C");
else if(60<=a&&a<70)
printf("D");
else printf("E");
return 0;
}