exercises 3.20

#include <iostream>
#include <string>
#include <vector>
using std::string;
using std::vector;
using namespace std;
extern void bline();

int main()
{
    int temp;
    vector<int> index;
    while(cin>>temp){
        index.push_back(temp);
    }
    
    for(decltype(index.size()) i=0;i<index.size()-1;++i){
        cout<<index[i]+index[i+1]<<endl;
    }
    
    for(decltype(index.size()) i=0;i<index.size()-1;i++){
        cout<<index[i]+index[index.size()-i-1]<<endl;
    }
    return 0;
}

void bline(){
    cout<<"------"<<endl;
}