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