#include <iostream>
#include <fstream>
#include <bits/stdc++.h>

using namespace std;

int main()
{
    string s1, s2, s3;
    //ifstream in("in.txt");

    cin >> s1 >> s2 >> s3;
    int n1 = s1.length(), n2 = s2.length(), n3 = s3.length();
    char z1[n1+1], z2[n2+1], z3[n3+1];
    strcpy(z1, s1.c_str());
    strcpy(z2, s2.c_str());
    strcpy(z3, s3.c_str());


    int illegalNumber1 = 50;
    int illegalNumber2 = 50;
    int illegalNumber3 = 50;
    bool run = 1;
    for(int i = 0; i < s1.length(); i++)
    {
        for(int j = 0; j < s2.length(); j++)
        {
            if(z1[i] == z2[j])
            {
                cout << s1 << " " << i+1 << " " << s2 << " " << j+1 << endl;
                illegalNumber1 = i;
                illegalNumber2 = j;
                run = 0;
                break;
            }
        }
        if(!run) break;
    }

    bool run1 = 1;
    for(int i = 0; i < s1.length(); i++)
    {
        for(int j = 0; j < s3.length(); j++)
        {
            if(z1[i] == z3[j] && i != illegalNumber1)
            {
                cout << s1 << " " << i+1 << " " << s3 << " " << j+1 << endl;
                illegalNumber1 = i;
                illegalNumber3 = j;
                run1 = 0;
                break;
            }
        }
        if(!run1) break;
    }

    if(run or run1)
    {
        bool run2 = 1;
        for(int i = 0; i < s2.length(); i++)
        {
            for(int j = 0; j < s3.length(); j++)
            {
                if(z2[i] == z3[j] && i != illegalNumber2 && j != illegalNumber3)
                {
                    cout << s2 << " " << i+1 << " " << s3 << " " << j+1 << endl;
                    run2 = 0;
                    break;
                }
            }
        if(!run2) break;
        }
    }


    return 0;
}

#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

int main()
{
    ifstream input("tvora-vyr.in");

    int N, V, Z, T;
    int laikas = 0;
    int dazymas = 0;
    int ilsetis = 0;
    cin >> N >> V >> Z >> T;
    vector<int> ValymoLaikai;
    for(int i = 1; i < N + 1; i++)
    {
        ValymoLaikai.push_back(V * i);
    }
    laikas = T;

    for(int i = 0; i < N; i++)
    {
        while(true)
        {
            if(laikas >= ValymoLaikai[i])
            {
                dazymas += Z;
                laikas += Z;
                break;
            }
            else ilsetis++;
            laikas++;

        }

    }

    cout << ilsetis;

    return 0;
}