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

import java.io.*;
import java.math.*;
import java.util.*;

public class SolutionA{

	public static void main(String[] args){
		new SolutionA().run();
	}
	int a, b, c;
	boolean check(int x){
		int sum = x * b;
		for(int i = 0; i < c; i++){
			sum += b;
			if(sum < a) return false;
			sum -= a;
		}
		return true;
	}
	void solve(){
		a = in.nextInt();
		b = in.nextInt();
		c = in.nextInt();
		int l = 0;
		int r = 1000000;
		int ans = 0;
		while( l <= r){
			int mid = (l + r) /2;
			if(check(mid)){
				ans = mid;
				r = mid-1;
			}
			else l = mid+1;
		}
		out.println(ans);
	}


	class Pair implements Comparable<Pair>{
		int x, y;
		Pair(int x, int y){
			this.x = x;
			this.y = y;
		}
		@Override
		public int compareTo(Pair o) {
			if(o.x == x) return ((Integer) y).compareTo(o.y); 
			return ((Integer) x).compareTo(o.x);
		}

	}
	FastScanner in;
	PrintWriter out;
	void run(){
		in = new FastScanner(System.in);
		out = new PrintWriter(new OutputStreamWriter(System.out));
		solve();
		out.close();
	}

	void runIO(){
		try{
			in = new FastScanner(new File("expr.in"));
			out = new PrintWriter(new FileWriter(new File("expr.out")));
			solve();
			out.close();
		}catch(Exception ex){
			ex.printStackTrace();
		}
	}
	class FastScanner{
		BufferedReader bf;
		StringTokenizer st;
		public FastScanner(File f){
			try{
				bf = new BufferedReader(new FileReader(f));
			}
			catch(IOException ex){
				ex.printStackTrace();
			}
		}
		public FastScanner(InputStream is){
			bf = new BufferedReader(new InputStreamReader(is));
		}
		String next(){
			while(st == null || !st.hasMoreTokens()){
				try{
					st = new StringTokenizer(bf.readLine());
				}
				catch(IOException ex){
					ex.printStackTrace();
				}
			}
			return st.nextToken();
		}
		char nextChar(){
			return next().charAt(0);
		}
		int nextInt(){
			return Integer.parseInt(next());
		}
		double nextDouble(){
			return Double.parseDouble(next());
		}
		float nextFloat(){
			return Float.parseFloat(next());
		}
		String nextLine(){
			try{
				return bf.readLine();
			}
			catch(Exception ex){
				ex.printStackTrace();
			}
			return "";
		}
		long nextLong(){
			return Long.parseLong(next());
		}
		BigInteger nextBigInteger(){
			return new BigInteger(next());
		}
		BigDecimal nextBigDecimal(){
			return new BigDecimal(next());
		}
		int[] nextIntArray(int n){
			int a[] = new int[n];
			for(int i = 0; i < n; i++)
				a[i] = Integer.parseInt(next());
			return a;
		}
		long[] nextLongArray(int n){
			long a[] = new long[n];
			for(int i = 0; i < n; i++)
				a[i] = Long.parseLong(next());
			return a;
		}
	}
}