# include<stdio.h>
int main()
{
  int m,t,s;
  scanf("%d %d %d",&m,&t,&s);
  float a;
  if(t==0){
    a=m;
  }else{
    a=s/t;
  }
  int b;
  if(a>=m-1){
    printf("0");
  }else{
    a=ceil(a);
    b=m-a;
    printf("%d",b);
  }
  return 0;
}