//#include <atcoder/all>
//using namespace atcoder;
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i, n) for(int i=0; i<n; i++)
#define REPR(i, n) for(int i=n-1; i>=0; i--)
#define FOR(i, m, n) for(int i=m; i<n; i++)
#define ALL(v) v.begin(), v.end()
#define bit(n) (1LL<<(n))
#define FIX(d) fixed << setprecision(d)
using P = pair<int, int>;
using LP = pair<ll, ll>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = 1e9;
const ll LINF = (1LL<<60);

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int x,y,z;
  cin >> x >> y >> z;
  REPR(i, 1000000){
    double p1 = (double)y / x;
    double p2 = (double)i / z;
    if(p1>p2){
      cout << i << endl;
      return 0;
    }
  }
  
  return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define vec vector<int>
#define vecp vector<pair<int,int>>
#define ll long long
#define ull unsigned long long
#define pb push_back
#define fi first
#define se second
#define fr1(i,a,b) for(int i=a;i<b;i++)
#define fr2(i,a,b) for(int i=a;i>=b;i--)
#define fr3(i,a,b) for(int i=a;i<=b;i++)
#define umap unordered_map<int,int>
#define omap map<int,int>
#define uset unordered set<int>
#define oset set<int>
#define pr pair<int,int>
#define endl "\n"


void solve()
{
    int a,b;
    cin>>a>>b;
    a=(2*a)+100;
    cout<<a-b<<endl;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t=1;
    //cin>>t;
    fr3(i,1,t){
        solve();
    }
}


