#include <stdio.h>

char getGrade(int score) {
    // Check for invalid score
    if (score < 0 || score > 100) {
        return 'I'; // Invalid grade
    }

    // Determine letter grade based on score
    if (score >= 90) {
        return 'A';
    } else if (score >= 80) {
        return 'B';
    } else if (score >= 70) {
        return 'C';
    } else if (score >= 60) {
        return 'D';
    } else {
        return 'F';
    }
}

int main() {
    int score;

    // Example usage
    printf("Enter the score: ");
    scanf("%d", &score);

    char grade = getGrade(score);
    if (grade == 'I') {
        printf("Invalid score entered.\n");
    } else {
        printf("The grade for a score of %d is: %c\n", score, grade);
    }

    return 0;
}