// Change the container type to show their characteristics.
//
// vector   - unsorted, duplicates allowed
// list     - unsorted, duplicates allowed
// string   - unsorted, duplicates allowed
// set      - sorted, duplicates forbidden
// multiset - sorted, duplicates allowed

#include <vector>
#include <list>
#include <set>
#include <string>
#include <iostream>				// for cout
#include <iomanip>				// for setprecision
#include <sstream>				// for ostringstream
#include <cmath>				// for atan

using namespace std;

int main() {
    ostringstream ss;
    ss << setprecision(20) << 4*atan(1.0L);
    const string pi = ss.str();		      // First twenty digits of π

    vector<char> digits(pi.begin(), pi.end());   // Fill it with digits

    for (auto d : digits)
	cout << d << ' ';
    cout << '\n';
}