text: #pragma region template 3.0
  #define G3(_1, _2, _3, F, ...) F
  #define G4(_1, _2, _3, _4, F, ...) F
  #define G5(_1, _2, _3, _4, _5, F, ...) F
  #define G6(_1, _2, _3, _4, _5, _6, F, ...) F
  #include <bits/stdc++.h>
  using namespace std;
  using ll = long long;
  template <typename T>
  using vec = vector<T>;
  template <typename T>
  using vec2 = vec<vec<T>>;
  template <typename T>
  using vec3 = vec<vec2<T>>;
  template <typename T>
  using vec4 = vec<vec3<T>>;
  using vi = vec<ll>;
  using vvi = vec2<ll>;
  using ii = pair<ll, ll>;
  using iii = tuple<ll, ll, ll>;
  using vii = vec<ii>;
  using vs = vec<string>;
  using vb = vec<bool>;
  template <typename T>
  using pq = priority_queue<T, vector<T>, greater<T>>;
  #define VEC1(T, n1) vec<T>(n1)
  #define VEC2(T, n1, n2) vec2<T>(n1, VEC1(T, n2))
  #define VEC3(T, n1, n2, n3) vec3<T>(n1, VEC2(T, n2, n3))
  #define VEC4(T, n1, n2, n3, n4) vec4<T>(n1, VEC3(T, n2, n3, n4))
  #define vec(...) G5(__VA_ARGS__, VEC4, VEC3, VEC2, VEC1)(__VA_ARGS__)
  #define VEC1V(T, n1, v) vec<T>(n1, v)
  #define VEC2V(T, n1, n2, v) vec2<T>(n1, VEC1V(T, n2, v))
  #define VEC3V(T, n1, n2, n3, v) vec3<T>(n1, VEC2V(T, n2, n3, v))
  #define VEC4V(T, n1, n2, n3, n4, v) vec4<T>(n1, VEC3V(T, n2, n3, n4, v))
  #define vecv(...) G6(__VA_ARGS__, VEC4V, VEC3V, VEC2V, VEC1V)(__VA_ARGS__)
  #define REP0(i, n) for (ll i = 0; i < (n); ++i)
  #define REP(i, j, n) for (ll i = (j); i < (n); ++i)
  #define rep(...) G3(__VA_ARGS__, REP, REP0)(__VA_ARGS__)
  #define REP1(i, n) for (ll i = 1; i <= (n); ++i)
  #define REPI(i, j, n) for (ll i = (j); i <= (n); ++i)
  #define repi(...) G3(__VA_ARGS__, REPI, REP1)(__VA_ARGS__)
  #define RREP0(i, n) for (ll i = (n)-1; i >= 0; --i)
  #define RREP(i, j, n) for (ll i = (n)-1; i >= (j); --i)
  #define rrep(...) G3(__VA_ARGS__, RREP, RREP0)(__VA_ARGS__)
  #define RREP1(i, n) for (ll i = (n); i >= 1; --i)
  #define RREPI(i, j, n) for (ll i = (n); i >= (j); --i)
  #define rrepi(...) G3(__VA_ARGS__, RREPI, RREP1)(__VA_ARGS__)
  #define each(i, a) for (auto &i : a)
  #define ch(f, x, y) x = f((x), (y))
  #define ALL(a) (a).begin(), (a).end()
  #define SORT(a) sort(ALL(a))
  #define RSORT(a) \
    SORT(a);       \
    reverse(ALL(a))
  #define IN1(T, a) \
    T a;            \
    cin >> a;
  #define IN2(T, a, b) \
    T a, b;            \
    cin >> a >> b;
  #define IN3(T, a, b, c) \
    T a, b, c;            \
    cin >> a >> b >> c;
  #define IN4(T, a, b, c, d) \
    T a, b, c, d;            \
    cin >> a >> b >> c >> d;
  #define in(...) G5(__VA_ARGS__, IN4, IN3, IN2, IN1)(__VA_ARGS__)
  #define ll(...) in(ll, __VA_ARGS__)
  #define STR(...) in(string, __VA_ARGS__)
  #define VIN1(T, a, n) \
    vec<T> a(n);        \
    each(i, a) cin >> i;
  #define VIN2(T, a, b, n) \
    vec<T> a(n), b(n);     \
    rep(i, n) cin >> a[i] >> b[i];
  #define VIN3(T, a, b, c, n) \
    vec<T> a(n), b(n), c(n);  \
    rep(i, n) cin >> a[i] >> b[i] >> c[i];
  #define VIN4(T, a, b, c, d, n)   \
    vec<T> a(n), b(n), c(n), d(n); \
    rep(i, n) cin >> a[i] >> b[i] >> c[i] >> d[i];
  #define vin(...) G6(__VA_ARGS__, VIN4, VIN3, VIN2, VIN1)(__VA_ARGS__)
  #define vll(...) vin(ll, __VA_ARGS__)
  #define vvll(a, n)       \
    vvi a = vec(ll, n, n); \
    rep(i, n) rep(j, n) cin >> a[i][j];
  #define out(x) cout << (x) << endl;
  #define fout(x) cout << fixed << setprecision(15) << (x) << endl;
  #define DUMP1(a) cout << #a << " = " << (a) << endl;
  #define DUMP2(a, b) \
    cout << #a << " = " << (a) << ' ' << #b << " = " << (b) << endl;
  #define DUMP3(a, b, c)                                                 \
    cout << #a << " = " << (a) << ' ' << #b << " = " << (b) << ' ' << #c \
         << " = " << (c) << endl;
  #define DUMP4(a, b, c, d)                                              \
    cout << #a << " = " << (a) << ' ' << #b << " = " << (b) << ' ' << #c \
         << " = " << (c) << ' ' << #d << " = " << (d) << endl;
  #define DUMP5(a, b, c, d, e)                                              \
    cout << #a << " = " << (a) << ' ' << #b << " = " << (b) << ' ' << #c    \
         << " = " << (c) << ' ' << #d << " = " << (d) << ' ' << #e << " = " \
         << (e) << endl;
  #define dump(...) \
    G5(__VA_ARGS__, DUMP5, DUMP4, DUMP3, DUMP2, DUMP1)(__VA_ARGS__)
  template <typename T>
  ostream &jout(T s, T e, string sep = " ", ostream &os = cout) {
    if (s != e) {
      os << *s;
      ++s;
    }
    while (s != e) {
      os << sep << *s;
      ++s;
    }
    return os;
  }
  ostream &yes(bool cond, string y = "Yes", string n = "No", ostream &os = cout) {
    os << (cond ? y : n) << endl;
    return os;
  }
  template <typename T1, typename T2>
  ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
    return os << '(' << p.first << ", " << p.second << ')';
  }
  template <typename T1, typename T2, typename T3>
  ostream &operator<<(ostream &os, const tuple<T1, T2, T3> &t) {
    return os << '(' << get<0>(t) << ", " << get<1>(t) << ", " << get<2>(t)
              << ')';
  }
  template <typename T>
  ostream &operator<<(ostream &os, const vector<T> &v) {
    return jout(ALL(v), ", ", os << '[') << ']';
  }
  template <typename T>
  ostream &operator<<(ostream &os, const set<T> &s) {
    return jout(ALL(s), ", ", os << '{') << '}';
  }
  template <typename K, typename V>
  ostream &operator<<(ostream &os, const map<K, V> &m) {
    return jout(ALL(m), ", ", os << '{') << '}';
  }
  const ll INF = 1e18;
  const ll MOD = 1e9 + 7;
  #pragma endregion template
  
  int main() {
    ll(L1, R1);
    ll(L2, R2);
    ll(L3, R3);
    ll d = (R1 - L1 + 1) * (R2 - L2 + 1) * (R3 - L3 + 1);
    ll n = 0;
    repi(i, L1, R1) {
      n += max(0LL, R2 - max(i, L2 - 1)) * max(0LL, R3 - max(i, L3 - 1));
    }
    fout((long double)(n) / d);
  }