#include <stdio.h>
int main() {
    char grade;
    scanf("%c", &grade);
    if (grade == 'A') {
        printf("Excellent!\n");
    } else if (grade == 'B') {
        printf("Good job\n");
    } else if (grade == 'C') {
        printf("Fair\n");
    } else if (grade == 'D') {
        printf("Needs improvement\n");
    } else if (grade == 'F') {
        printf("Failed\n");
    } else {
        printf("Invalid grade\n");
    }
}

#include <stdio.h>
int main() {
    char grade;
    scanf("%c", &grade);

    switch (grade) {
    case 'A':
        printf("Excellent!\n");
        break;
    case 'B':
        printf("Good job\n");
        break;
    case 'C':
        printf("Fair\n");
        break;
    case 'D':
        printf("Needs improvement\n");
        break;
    case 'F':
        printf("Failed\n");
        break;
    default:
        printf("Invalid grade\n");
    }
}

switch (value) {
    case case1:
        // Body if case1
        break;
    case case2:
        // Body if case2
        break;
    // Add more cases if needed
    case default:
        // Body if no other case
}

switch (day) {
    case 1: printf("Monday\n"); break;
    case 2: printf("Tuesday\n"); break;
    case 3: printf("Wednesday\n"); break;
    case 4: printf("Thursday\n"); break;
    case 5: printf("Friday\n"); break;
    case 6: printf("Saturday\n"); break;
    case 7: printf("Sunday\n"); break;
    default: printf("Invalid day\n");
}

#include <stdio.h>
int main() {
    char op;
    double a, b;
    printf("Enter an operator (+, -, *, /, %%, ^): ");
    scanf(" %c", &op);
    printf("Enter two numbers: ");
    scanf("%lf %lf", &a, &b);
    switch (op) {
        case '+':
            printf("Result = %.2f\n", a + b);
            break;
        case '-':
            printf("Result = %.2f\n", a - b);
            break;
        case '*':
            printf("Result = %.2f\n", a * b);
            break;
        case '/':
            if (b != 0) {
                printf("Result = %.2f\n", a / b);
            } else {
                printf("Error: division by zero\n");
            }
            break;
        default:
            printf("Unknown operator\n");
    }
}

#include <stdio.h>
int main() {
    int month;
    printf("Enter month (1–12): ");
    scanf("%d", &month);
    switch (month) {
        case 2:
            printf("28 or 29 days\n");
            break;
        case 4:
        case 6:
        case 9:
        case 11:
            printf("30 days\n");
            break;
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12:
            printf("31 days\n");
            break;
        default:
            printf("Invalid month\n");
    }
    return 0;
}