hdoj no.2004

#include<stdio.h>
int main()
{
    int score;
    int input;

    input=scanf("%d",&score);
    while(input!=EOF)
    {
        if(score>=90&&score<=100) printf("A\n");
        if(score>=80&&score<=89) printf("B\n");
        if(score>=70&&score<=79) printf("C\n");
        if(score>=60&&score<=69) printf("D\n");
        if(score>=0&&score<=59) printf("E\n");
        if(!(score>=0&&score<=100)) printf("Score is error!\n");
        input=scanf("%d",&score);   
    }
}