#include <stdio.h>
 
int main()
{
    unsigned long long int a,b,n;
    scanf("%llu %llu %llu",&a, &b,&n);
    unsigned long long int max=0;
    unsigned long long int ans=0;
    if(b<=n)
    {
    for(int i = b-1;i<=n;i+=b){
    ans=((i*a)/b)-a*(i/b);
     printf("%d %llu\n",i,ans);
    if(ans>max){
    max=ans;
    }
    }
    }
    else{
    ans=((n*a)/b)-a*(n/b);
    if(ans>max){
        max=ans;
                }
        }
        
     printf("%llu",max);
    return 0;
}