#include <stdio.h>
int main() {
    int score;
    char grade;
    scanf("%d", &score);
    if(score >= 90) {
        grade = 'A';
    } else if(score >= 80) {
        grade = 'B';
    } else if(score >= 70) {
        grade = 'C';
    } else if(score >= 60) {
        grade = 'D';
    } else {
        grade = 'F'; 
    }
    printf("Your grade is %c\n", grade);
}

if(5 > 7) {
    printf("5 is greater than 7\n");
} else if(5 < 7) {
    printf("5 is smaller than 7\n");
} else if(1 > 0) {
    printf("1 is greater than 0\n");
}

#include <stdio.h>
int main() {
    int ADULT = 18, SENIOR = 65;
    int age;
    scanf("%d", &age);
    if(age >= ADULT) {
        printf("You are an adult\n");
        if(age >= SENIOR) {
            printf("You are a senior\n");
        } else {
            printf("You are not a senior\n");
        }
    } else {
        printf("You are not an adult\n");
    }
}

#include <stdio.h>
int main() {
    int val = 0;
    if (val > 0)
        printf("Positive\n");
        printf("Check complete\n");
    else
        printf("Non-positive\n");
    return 0;
}