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

}