#include<bits/stdc++.h> using namespace std; int qiu_he(int a,int b){ int sum=0; for(int i=a;i<=b;i++){ sum+=i; } return sum; } int main(){ cout<<qiu_he(1,10)<<endl; cout<<qiu_he(20,30)<<endl; cout<<qiu_he(35,45); return 0; }