import sys

input = sys.stdin.readline



A, B, N = list(map(int,input().split()))

x = 0



if N >= B:

    x = B-1

else:

    x = N



print((A*x//B))

import sys

sys.stdin.readline



A, B, N = list(map(int, input().split()))

ans = 0



if N >= B:

    ans = B-1

else:

    ans = N



print((A * ans //B))

import sys

input = sys.stdin.readline
A, B, N = list(map(int, input().split()))
x = 0
if N >= B:
    x = B - 1
else:
    x = N
print((A * x // B))

import sys

sys.stdin.readline
A, B, N = list(map(int, input().split()))
ans = 0
if N >= B:
    ans = B - 1
else:
    ans = N
print((A * ans // B))

-input = sys.stdin.readline +sys.stdin.readline -x = 0 +ans = 0 -    x = B - 1 +    ans = B - 1 -    x = N -print((A * x // B)) +    ans = N +print((A * ans // B))