stack 74 (7) (IRA)

#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>
#include <stack>
#include <queue>

using namespace std;


ifstream fin("input.txt");


int main()
{
    /*
    1 2 2 3 3 3 4 4 4 4
    */
    stack<int> s;
    while (fin.peek() != EOF)
    {
        int cur;
        fin >> cur;
        if (s.empty() || s.top() != cur)
            s.push(cur);
    }
    while (!s.empty())
    {
        int cur = s.top();
        s.pop();
        cout << cur << ' ';
    }
    cout << endl;
}