3-4. 成绩转换(15)

#include <stdio.h>

int main()
{
int a;
scanf("%d",&a);

const int A = 90;
const int B = 80;
const int C = 70;
const int D = 60;

if(a < A){
if(a < B){
if(a < C){
if(a < D){
printf("E\n");
}
else{
printf("D\n");
}
}
else{
printf("C\n");
}
}
else{
printf("B\n");
}
}
else{
printf("A\n");
}

return 0;
}