#include <stdio.h>
#include<math.h>
int main() {
int n,h,m;
scanf("%d%d%d",&n,&h,&m);
int b=ceil((double)m/h);
printf("%d",n-b);
return 0;
}

#include <stdio.h>
#include<math.h>
int main() {
int n,h,m;
scanf("%d%d%d",&n,&h,&m);
int b=ceil((double)m/h);
printf("%d",n-b);
return 0;
}