#include <fstream>
#include <iostream>

using namespace std;

ifstream in("rufe.in");
ofstream out("rufe.out");

long long ROWS, COLS, SOCK_X, SOCK_Y, SHIRTS;

long long distance(long long x_1,
                            long long y_1,
                            long long x_2,
                            long long y_2) {
    return abs(x_1 - x_2) + abs(y_1 - y_2);
}

long long get_max_distance() {
    long long max_dist = distance(SOCK_X - 1, SOCK_Y - 1, 0, 0);

    long long dist = distance(SOCK_X - 1, SOCK_Y - 1, 0, ROWS - 1);
    if (dist > max_dist)
        max_dist = dist;

    dist = distance(SOCK_X - 1, SOCK_Y - 1, COLS - 1, 0);
    if (dist > max_dist)
        max_dist = dist;

    dist = distance(SOCK_X - 1, SOCK_Y - 1, COLS - 1, ROWS - 1);
    if (dist > max_dist)
        max_dist = dist;

    return max_dist;
}

unsigned long long delta_yn(long long dist) {
    if (SOCK_Y - 1 - dist >= 0)
        return 0;

    return abs(SOCK_Y - 1 - dist) - 1;
}

unsigned long long delta_xn(long long dist) {
    if (SOCK_X - 1 - dist >= 0)
        return 0;

    return abs(SOCK_X - 1 - dist) - 1;
}

unsigned long long delta_yp(long long dist) {
    if (SOCK_Y - 1 + dist <= ROWS - 1)
        return 0;

    return SOCK_Y + dist - ROWS - 1;
}

unsigned long long delta_xp(long long dist) {
    if (SOCK_X - 1 + dist <= COLS - 1)
        return 0;

    return SOCK_X + dist - COLS - 1;
}

unsigned long long get_outsiders(long long distance) {
    return delta_yn(distance) + delta_xn(distance) +
           delta_yp(distance) + delta_xp(distance);
}

int main() {
    in >> ROWS >> COLS >> SOCK_Y >> SOCK_X >> SHIRTS;
    long long distance = get_max_distance();

    while (SHIRTS > 0) {
        unsigned long long outsiders = get_outsiders(distance);

        SHIRTS -= distance * 4 - outsiders;

        distance--;
    }

    out << distance << endl;

    return 0;
}