def n0():return int(eval(input()))

def n1():return [int(x) for x in input().split()]

def n2(n):return [int(eval(input())) for _ in range(n)]

def n3(n):return [[int(x) for x in input().split()] for _ in range(n)]



a,b,n=n1()



if b<=n:

    i=b-1

else:

    i=n

m=(a*i)//b-a*(i//b)

print(m)
def n0():return int(eval(input()))

def n1():return [int(x) for x in input().split()]

def n2(n):return [int(eval(input())) for _ in range(n)]

def n3(n):return [[int(x) for x in input().split()] for _ in range(n)]

 

a,b,n=n1()

import math

if b<=n:

    i=b-1

else:

    i=n

m=math.floor((a*i)/b)-a*math.floor(i//b)

print(m)

def n0():
    return int(eval(input()))


def n1():
    return [int(x) for x in input().split()]


def n2(n):
    return [int(eval(input())) for _ in range(n)]


def n3(n):
    return [[int(x) for x in input().split()] for _ in range(n)]


a, b, n = n1()
if b <= n:
    i = b - 1
else:
    i = n
m = (a * i) // b - a * (i // b)
print(m)

def n0():
    return int(eval(input()))


def n1():
    return [int(x) for x in input().split()]


def n2(n):
    return [int(eval(input())) for _ in range(n)]


def n3(n):
    return [[int(x) for x in input().split()] for _ in range(n)]


a, b, n = n1()
import math

if b <= n:
    i = b - 1
else:
    i = n
m = math.floor((a * i) / b) - a * math.floor(i // b)
print(m)

+import math + -m = (a * i) // b - a * (i // b) +m = math.floor((a * i) / b) - a * math.floor(i // b)