if-else

#include <stdio.h>#include <stdlib.h>int main(){    int score,grade;    printf("Input  score  ");    scanf("%d",&score);    grade=score<0||score>100?-1:score/10;    if(score>=90&&score<=100)    {        printf("A");    }    else if(score>=80&&score<90)    {       printf("B");    }    else if(score>=70&&score<80)    {       printf("C");    }    else if(score>=60&&score<70)    {       printf("D");    }    else if(score>=0&&score<60)    {       printf("E");    }    return 0;}