a=input()
n,x,y = int(a.split()[0]),int(a.split()[1]),int(a.split()[2])
if y/x != y//x:
    b=n-y//x-1
else:
    b=n-y//x
if b<0:
    b=0
print(b)

#include <iostream>
using namespace std;
int main(){
    int n, x, y, m;
	cin >> n >> x >> y;
    if(y % x == 0)
        m = n - y / x;
    else
        m = n - y / x - 1;
	if(m > 0)
        cout << m << endl;
    else
        cout << 0 << endl;
	return 0;
}