using namespace std; #ifndef INCLUDED_MAIN #define INCLUDED_MAIN #include __FILE__ int A, B, C, D, E; void input() { cin >> A >> B >> C >> D >> E; } void solve() { int F = B - C; int ans = 0; rep(i, 1, F * A + 1) { if(i % 10 == 0 && E <= D) D -= E; ans += D; } out(ans); } int main() { cin.tie(nullptr); ios_base::sync_with_stdio(false); cout << fixed << setprecision(15); int t = 1; while(t--) { input(); solve(); } } #else // INCLUDED_MAIN #include template using vp = vector>; template using pque = priority_queue; template using lpque = priority_queue, greater>; template using umap = unordered_map; template using uset = unordered_set; using lint = long long; using pint = pair; using plint = pair; using pil = pair; using pli = pair; using vint = vector; using vlint = vector; using vpint = vector; using vplint = vector; using vpil = vector; using vpli = vector; using vbl = vector; using qint = queue; using qlint = queue; constexpr double PI = 3.141592653589793; constexpr int INTINF = (1 << 30) - 1; constexpr lint LLINF = (1LL << 62) - 1; constexpr int MPRIME = 1000000007; constexpr int MPRIME9 = 998244353; constexpr lint MMPRIME = (1LL << 61) - 1; constexpr char newl = '\n'; #define len length() #define empb(...) emplace_back(__VA_ARGS__) #define fi first #define se second #define get_rep(_1, _2, _3, func, ...) func #define rep(i, ...) get_rep(__VA_ARGS__, rep3, rep2, rep1)(i, __VA_ARGS__) #define rep1(i, N) for(int i = 0; i < (N); i++) #define rep2(i, s, t) for(int i = (s); i < (t); i++) #define rep3(i, s, t, a) for(int i = (s); i < (t); i += (a)) #define get_rrep(_1, _2, _3, func, ...) func #define rrep(i, ...) get_rrep(__VA_ARGS__, rrep3, rrep2, rrep1)(i, __VA_ARGS__) #define rrep1(i, N) for(int i = (N); i >= 0; i--) #define rrep2(i, s, t) for(int i = (s); i >= (t); i--) #define rrep3(i, s, t, a) for(int i = (s); i >= (t); i -= (a)) #define forbit(bit, k) for(int bit = 0; bit < (1 << (k)); bit++) #define forsubset(bit, orig_bit) \ for(int bit = (orig_bit), _cnt = 0; (_cnt += (bit == (orig_bit))) < 2; --bit &= (orig_bit)) #define bitpop(bit, k) (((bit) >> (k)) & 1) #define all(name) name.begin(), name.end() #define rall(name) name.rbegin(), name.rend() #define gsort(vbeg, vend) sort(vbeg, vend, greater<>()) template inline bool chmin(T &a, T b) { if(a > b) { a = b; return true; } return false; } template inline bool chmax(T &a, T b) { if(a < b) { a = b; return true; } return false; } template inline void init(vector &v) { for(auto &a : v) cin >> a; } template inline void init(vector> &v) { for(auto &a : v) cin >> a.first >> a.second; } template inline void init(vector &v, int n) { v.resize(n); for(auto &a : v) cin >> a; } template inline void init(vector &v1, vector &v2, int n) { v1.resize(n); v2.resize(n); for(int i = 0; i < n; i++) cin >> v1[i] >> v2[i]; } template inline void init(vector &v1, vector &v2, vector &v3, int n) { v1.resize(n); v2.resize(n); v3.resize(n); for(int i = 0; i < n; i++) cin >> v1[i] >> v2[i] >> v3[i]; } template inline void init(vector> &v, int n) { v.resize(n); for(auto &a : v) cin >> a.first >> a.second; } template inline void init(vector &v, int n, const T &c) { v.resize(n); for(auto &a : v) { cin >> a; a += c; } } template inline void init(vector &v1, vector &v2, int n, const T1 &c1, const T2 &c2) { v1.resize(n); v2.resize(n); for(int i = 0; i < n; i++) { cin >> v1[i] >> v2[i]; v1[i] += c1; v2[i] += c2; } } template inline void init(vector &v1, vector &v2, vector &v3, int n, const T1 &c1, const T2 &c2, const T3 &c3) { v1.resize(n); v2.resize(n); v3.resize(n); for(int i = 0; i < n; i++) { cin >> v1[i] >> v2[i] >> v3[i]; v1[i] += c1; v2[i] += c2; v3[i] += c3; } } template inline void init(vector> &v, int n, T &c1, U &c2) { v.resize(n); for(auto &a : v) { cin >> a.first >> a.second; a.first += c1; a.second += c2; } } inline void out() { cout << newl; } template inline void out(T a) { cout << a << '\n'; } template inline void out(T a, U... lst) { cout << a << " "; out(forward(lst)...); } template inline void out(vector &v) { for(int i = 0; i < v.size(); i++) cout << v[i] << (i == v.size() - 1 ? '\n' : ' '); cout << flush; } template void resiz(N n) {} template void resiz(N n, T &&hd, U &&...tl) { hd.resize(n); resiz(n, forward(tl)...); } bool Yes(bool b = true) { cout << (b ? "Yes" : "No") << newl; return b; } bool YES(bool b = true) { cout << (b ? "YES" : "NO") << newl; return b; } bool No(bool b = true) { if(!b) return false; cout << "No" << newl; return true; } bool NO(bool b = true) { if(!b) return false; cout << "NO" << newl; return true; } template struct v2d { private: vector> m; public: v2d() {} v2d(int h, int w) : m(h, vector(w)) {} v2d(int h, int w, const T &init) : m(h, vector(w, init)) {} v2d(const initializer_list> m_init) : m(m_init.begin(), m_init.end()) {} void assign(int h, int w) { m.assign(h, vector(w)); } void assign(int h, int w, const T init) { m.assign(h, vector(w, init)); } inline int size() const { return m.size(); } void in() { for(vector &v : m) for(T &val : v) cin >> val; } void in(int h, int w) { m.resize(h, vector(w)); in(); } void out() { int h = m.size(); for(vector &v : m) { int sz = v.size(); for(int j = 0; j < sz; j++) { cout << v[j] << (j == sz - 1 ? '\n' : ' '); } } cout << flush; } inline vector &operator[](int idx) { assert(0 <= idx && idx < m.size()); return m[idx]; } }; long long binpow(long long a, long long ex, long long p = MMPRIME) { long long res = 1; while(ex > 0) { if(ex & 1) (res *= a) %= p; ex >>= 1; (a *= a) %= p; } return res; } #endif // INCLUDED_MAIN