C - 成绩转换

#include<stdio.h>
int main()
{
    int x;
    while(scanf("%d",&x)!=EOF)
    {
        if(x>100)
            printf("Score is error!\n");
        else if
           (x>=90)printf("A\n");
        else if
           (x>=80)printf("B\n");
        else if
           (x>=70)printf("C\n");
        else if
           (x>=60)printf("D\n");
        else if
           (x>=0)printf("E\n");
        else
            printf("Score is error!\n");
    }
    return 0;
}