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