#include"stdio.h"
main()
{int m,t,s,a,b,c;
scanf("%d%d%d",&m,&t,&s);
if(t==0)
printf("%d",0);
if(t!=0)
{
b=s/t;
c=m-b;
if(c>=0) 
printf("%d",c);
if(c<0)
printf("%d",0);}
return 0;
}