#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(ll i=0;i<n;++i)
#define ocut cout
#define ouct cout
#define itn int

struct Union{
  vector<ll> par;
  Union(ll a){
  par=vector<ll>(a,-1);
  }
  ll find(ll a){
    if(par[a]<0){
      return a;
    }
    else{
      return par[a]=find(par[a]);
    }
  }
  bool same(ll a,ll b){
    return (find(a)==find(b));
  }
  ll size(ll a){
    return -par[find(a)];
  }
  void unite(ll a,ll b){
    ll c=find(a),d=find(b);
    if(c==d)
      return;
    if(size(c)<size(d)){
      swap(c,d);
    }
    par[c]+=par[d];
    par[d]=c;
  }
};
ll euclidean_gcd(ll a, ll b) {
  if(a < b) return euclidean_gcd(b, a);
  ll r;
  while ((r=a%b)) {
    a = b;
    b = r;
  }
  return b;
}
ll euclidean_lcm(ll a, ll b) {
  return a/euclidean_gcd(a,b)*b;
}

class smart_sieve {
  intmax_t L, R, M;
  std::vector<int> small;  // 小さい篩
  std::vector<std::vector<intmax_t>> large;  // 大きい篩
  std::vector<intmax_t> aux;  // aux[i] := large[i] の素因数の積

public:
  smart_sieve(intmax_t L, intmax_t R): L(L), R(R), M(sqrt(R)+1) {
    small.resize(M);
    std::iota(small.begin(), small.end(), 0);
    large.resize(R-L);
    aux.assign(R-L, 1);

    for (intmax_t i = 2; i*i < R; ++i) {
      if (small[i] < i) continue;
      small[i] = i;
      for (intmax_t j = i*i; j < M; j += i)
        if (small[j] == j) small[j] = i;

      for (intmax_t j = (L+i-1)/i*i; j < R; j += i) {
        intmax_t k = j;
        do {
          // aux[j-L] > M で判定した方がいいかも？
          // j / aux[j-L] < M の方がいい？（割り算したくない）
          if (aux[j-L] * aux[j-L] > R) break;

          large[j-L].push_back(i);
          aux[j-L] *= i;
          k /= i;
        } while (k % i == 0);
      }
    }
  }

  std::vector<intmax_t> factor(intmax_t n) {
    assert(L <= n && n < R);
    std::vector<intmax_t> res = large[n-L];
    n /= aux[n-L];
    if (n >= M) {
      // この場合，n は素数となることが示せる（はず）
      // n*n >= R だとオーバーフローしそう？
      res.push_back(n);
      return res;
    }
    while (n > 1) {
      res.push_back(small[n]);
      n /= small[n];
    }
    return res;
  }
};

int main(void){
  ll x,y,z;
  cin >> x >> y >> z;
  if(y*z%x==0)cout << y*z/x-1;
  else cout << y*z/x;
}
#include "bits/stdc++.h"
using namespace std;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    long double a = 0, b = 0, c = 0, d = 0, e = 0, f = 0, m = 0, n = 0, p = 0, q = 0, mod = 1000000007, pi = 3.1415926535;
    string s;
    char moji;
    cin >> a >> b >> c;
    d=floor(c*(b/a));
    cout << (d/c==b/a?d-1:d);
    return 0;
}