hohahola
#pragma comment(linker, "/STACK:102400000,102400000") #include<stdio.h> #include<string.h> #include<stdlib.h> #include<vector> #include<algorithm> #include<iostream> #include<map> #include<queue> #include<stack> #include<string> #include<functional> #include<math.h> //#include<bits/stdc++.h> using namespace std; typedef long long lint; typedef vector<int> VI; typedef pair<int, int> PII; typedef queue<int> QI; void makedata() { freopen("input.txt", "w", stdout); fclose(stdout); } int main() { #ifndef ONLINE_JUDGE freopen("input.txt", "r", stdin); #endif //makedata(); std::ios::sync_with_stdio(0), cin.tie(0); lint n, x, y, z; cin >> n >> x >> y >> z; if (z >= y) cout << (n * z / x) << endl; else { lint l = 0, r = n, mid; lint ans = 0; while (l + 1 < r) { mid = (l + r) / 2; if ((n - mid) * z >= (x - y) * mid) { l = mid; ans = max(ans, mid); } else r = mid; } cout << ans << endl; } return 0; }