Cod sursă (job #336249)

#include <fstream>

using namespace std;

ifstream cin("scv.in");
ofstream cout("scv.out");

long long C, T, M, Target;

int main()
{
    cin >> C >> T >> M >> Target;
    long long Zile = 0, Cant = 0, ProdZi = M;
    while(Cant < Target)
    {
        while(Cant < Target && Cant < C)
        {
            Zile++;
            Cant += ProdZi;
        }
        if(Cant + ProdZi * (C / M + T) < Target)
        {
            Zile += T;
            Cant += ProdZi * T - C;
            ProdZi += M;
        }
        else
        {
            while(Cant < Target)
            {
                Zile++;
                Cant += ProdZi;
            }
        }
    }
    cout << Zile;
    return 0;
}