Elevator Trouble

#include <iostream>

using namespace std;

#define ll long long

int main()
{
	cin.sync_with_stdio(false);
	ll f,s,g,u,d;
	cin >> f >> s >> g >> u >> d;
	if (u == 0 && d == 0) {
		if (s != g) cout << "use the stairs\n";
		else cout << 0 << "\n";
	} else if (u == 0) {
		if (g > s || (s-g)%d != 0) cout << "use the stairs\n";
		else cout << (s-g)/d << "\n";
	} else if (d == 0) {
		if (g < s || (g-s)%u != 0) cout << "use the stairs\n";
		else cout << (g-s)/u << "\n";
	} else {
		ll t = u-d;
		if (g > s) {
			if ((g-s)%u != t) cout << "use the stairs\n";
			else cout << (g-s)/u + 2*((g-s)%u) << "\n";
		} else if (g < s) {
			if ((s-g)%d != t) cout << "use the stairs\n";
			else cout << (s-g)/d + 2*((s-g)%d) << "\n";
		} else {
			cout << 0 << "\n";
		}
	}
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED