993 992 991
 100 1 10
 960 935 994
 99 8 99
 60 16 1
 759 10 258
 24 19 9
 196 169 144
 1000 999 1
 945 812 917
 1000 100 10
 500 300 300
 888 777 1000
 2 1 4
 24 12 12
 767 2 514
 2 1 2
 1000 1 1
 5 2 1
 70 32 1
 765 123 899
 17 7 10
 5 4 10
 888 777 888
 66 38 4
 1000 999 1000
 9 3 300
 244 87 4
 765 123 45
 1000 1 1000
 305 203 421
 100 10 1
 64 12 8
 894 1 999
 2 1 1
 18 14 10
 6 2 4
 888 777 1
 27 26 1
 2 1 3
 5 1 5
 7 3 200
 561 31 917
 17 10 7
 93 74 831

1
 990
 27
 1127
 3
 19325
 3
 24
 1
 151
 90
 200
 143
 4
 12
 196605
 2
 999
 2
 2
 4693
 15
 3
 127
 3
 2
 600
 8
 235
 999000
 212
 9
 35
 892107
 1
 3
 8
 1
 1
 3
 20
 267
 15678
 5
 214

#include <bits/stdc++.h>
using namespace std;
long long spf[100001];
vector<vector<long long>> adj(200001);
long long dx[4] = {1, -1, 0, 0};
long long dy[4] = {0, 0, 1, -1};
vector<vector<long long>> vis;
long long n, m;
vector<vector<long long>> arr(200, vector<long long>(200));
void dfs(long long i, long long j, long long n, long long m) {
  for (long long z = 0; z < 4; z++) {
    long long nx = dx[z] + i;
    long long ny = dy[z] + j;
    if (nx >= 0 && ny >= 0 && nx < n && ny < m && arr[nx][ny] == 1) {
      if (arr[i][j] == 2) {
        arr[nx][ny] = 3;
        dfs(nx, ny, n, m);
      }
      if (arr[i][j] == 3) {
        arr[nx][ny] = 2;
        dfs(nx, ny, n, m);
      }
    }
  }
}
void sieve() {
  spf[1] = 1;
  for (long long i = 2; i < 100001; i++) {
    spf[i] = i;
  }
  for (long long i = 4; i < 100001; i += 2) {
    spf[i] = 2;
  }
  for (long long i = 3; i * i < 100001; i++) {
    if (spf[i] == i) {
      for (long long j = i * i; j < 100001; j += i) {
        if (spf[j] == j) {
          spf[j] == i;
        }
      }
    }
  }
}
vector<long long> pf(long long i) {
  vector<long long> k;
  while (i != 1) {
    long long temp = spf[i];
    k.push_back(temp);
    while (i % temp == 0) {
      i = i / temp;
    }
  }
  return k;
}
void solve() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long d = 0;
  for (long long i = 0; i <= 1000; i++) {
    if (b * i + c * b >= a * c) {
      d = i;
      break;
    }
  }
  cout << d << endl;
}
signed main() {
  long long t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
