#include<stdio.h>
int main() {
    int lower_age,upper_age;
    scanf("%d %d",lower_age,upper_age);
    if(lower_age<0||upper_age<0||lower_age>upper_age) {
        printf("Invalid input\n");
    }
    else {
        int sum = 0;
        for(int i=lower_age;i<=upper_age;i++) {
            sum+=1;
        }
    }
    return 0;
}