#include using namespace std; struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star; #define all(c) (c).begin(), (c).end() #define rall(c) (c).rbegin(), (c).rend() #define vv(type, c, m, n, i) vector> c(m, vector(n, i)) #define rep(i,a,n) for(int i=(a), i##_len=(n); ii##_len; --i) #define len(x) ((int)(x).size()) #define mp make_pair #define eb emplace_back #define em emplace #define pb pop_back #define fi first #define se second #define get(a, i) get(a) typedef long long ll; typedef long double ld; typedef vector vi; typedef vector vd; typedef vector vll; typedef vector vs; typedef vector vb; typedef pair pii; #define mini min_element #define maxi max_element #define sum(a, b) accumulate(a, b) #define chmax(a,b) if(ab)a=b #define ce(x, y) (x + y - 1) / y template inline void print(T t){cout << t << "\n";} template inline void print(H h, T... t){cout << h << " ";print(t...);} int main() { int n, d; cin >> n >> d; if (n % d == 0) { print(n / d - 1); } else { print(n - 1); } return 0; }