#include <bits/stdc++.h>
#define db double
#define il inline
#define re register
#define ll long long
#define ui unsigned
#define ull ui ll
#define i128 __int128
#define pii pair<int, int>
#define fi first
#define se second
#define eb emplace_back
#define SZ(v) (int)v.size()
#define ALL(v) v.begin(), v.end()
#define mems(v, x) memset(v, x, sizeof(v))
#define memc(a, b) memcpy(a, b, sizeof(a))
#define FOR(i, L, R) for(re int i = (L); i <= (R); ++i)
#define ROF(i, R, L) for(re int i = (R); i >= (L); --i)
#define LS i << 1, l, mid
#define RS i << 1 | 1, mid + 1, r
#define popc(x) __builtin_popcount(x)
using namespace std;
#define N 200005
#define P 1000000007
il int add(int x, int y) {return x + y < P ? x + y : x + y - P;}
il void addr(int &x, int y) {(x += y) >= P && (x -= P);}
il int qpow(int p, int n = P - 2) {
  int s = 1;
  while(n) {
    if(n & 1) s = 1ll * s * p % P;
    p = 1ll * p * p % P, n >>= 1;
  }
  return s;
}
const int mu = qpow(1e4);
int n, m, L, R;
struct edge {
  int u, v, a, b;
} e[N];
ll w[N]; int p[N], f[N];
il int F(int x) {return f[x] ^ x ? f[x] = F(f[x]) : x;}
il ll calc(int mid) {
  // cerr << mid << "\n";
  FOR(i, 1, n) f[i] = i;
  FOR(i, 1, m) w[i] = e[i].a + 1ll * mid * e[i].b, p[i] = i;
  sort(p + 1, p + 1 + m, [](int x, int y) {return w[x] < w[y];});
  ll ns = 0;
  FOR(t, 1, m) {
    int i = p[t];
    int x = F(e[i].u), y = F(e[i].v);
    if(x ^ y) f[y] = x, ns += w[i];
  }
  return ns;
}
il void WORK() {
  FOR(i, 1, m) {
    auto &[u, v, a, b] = e[i];
    cin >> u >> v >> a >> b;
  }
  ll ans = 1e18;
  // while(L < R) {
  //   int mid = (L + R) >> 1;
  //   ll A = calc(mid), B = calc(mid + 1);
  //   if(A > B) ans = min(ans, B), L = mid + 1;
  //   else ans = min(ans, A), R = mid - 1;
  // }
  // while(L <= R) ans = min(ans, calc(L++));
  // cout << ans << "\n";
  cout << min(calc(L), calc(R)) << "\n";
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
  while(cin >> n >> m >> L >> R) WORK();
  cerr << 1.0 * clock() / CLOCKS_PER_SEC;
  return 0;
}