#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

typedef unsigned long long u64;

u64 div64_u64_rem(u64 a, u64 b, u64 *rem)
{
	u64 res = a / b;
	*rem = a % b;

	return res;

}

u64 div64_u64(u64 a, u64 b)
{
	return a / b;
}

u64 scale_stime(u64 stime, u64 rtime, u64 total)
{
        u64 rem, res, scaled;

        if (rtime >= total) {
                res = div64_u64_rem(rtime, total, &rem);
                scaled = stime * res;
                scaled += div64_u64(stime * rem, total);
        } else {
                res = div64_u64_rem(total, rtime, &rem);
                scaled = div64_u64(stime, res);
                scaled -= div64_u64(scaled * rem, total);
	}
	
	return scaled;
}

int main(int argc, char *argv[])
{
	u64 rtime, total, stime, scaled;

	if (argc != 4)
		return -1;

	rtime = strtoll(argv[1], NULL, 10);
	total = strtoll(argv[2], NULL, 10);
	stime = strtoll(argv[3], NULL, 10);

	assert (total >= stime);
	
	scaled = scale_stime(stime, rtime, total);
	printf("%llu\n", scaled);

	return 0;
}