#include <stdio.h>

int main () {

int student; /*declaration*/

printf("Enter your score, and I will tell you what is your score\n");

while (student)

{

printf("What is your score : ");

if (scanf("%d",&student) == 1)

 {

 {

 printf("Your grade is = ");

 if (student >= 90)

 printf("Your grade is %c \n\n", 'A');

 else

 if (student >= 80)

 printf("Your grade is %c \n\n", 'B');

 else

 if (student>=70)

 printf("Your grade is %c \n", 'C');

 else

 if (student>=60)

 printf("Your grade is %c \n", 'D');

 else

 printf("Your grade is %c \n", 'E');

 }

 }

 else

 {

 printf("You cannot input a letter");

 }

 }

return (0);

}