#include <iostream>
#include <vector>
using namespace std;

int main() {
	vector<float> X{1.f, 2.f, 3.f, 4.f, 5.f};
	cout << "before: "; for(auto f : X) { cout << f << " "; } cout << endl;
	X.erase(X.end()-3, X.end());
	cout << "after: "; for(auto f : X) { cout << f << " "; } cout << endl;
	return 0;
}