if嵌套 阶梯判断

#include<stdio.h>
int main(){
    int int_score;
    printf("%s", "Please enter a score: ");
    scanf("%d", &int_score);

    if(int_score > 90){
        printf("%s", "A");
    }
    else{
        if(int_score > 80){
            printf("%s", "B");
        }
        else{
            if(int_score > 70){
                printf("%s", "C");
            }
            else{
                if(int_score > 60){
                    printf("%s", "D");
                }
                else{
                    printf("%s", "E");
                }
            }
        }
    }

    return 0;
}