#include <string>
#include <vector>

using namespace std;

long long solution(int a, int b) {
    long long answer = 0;
    int firstNum,secondNum;
    
    if(a > b){
        firstNum = b;
        secondNum = a;
    } else {
        firstNum = a;
        secondNum = b;
    }
    
    for(int i=firstNum;i<=secondNum;i++){
        answer+=i;
    }
    return answer;
}