import math

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

ans = math.floor(A*min(N, B-1)/B) - A*math.floor(min(N, B-1)/B)

print(ans)

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

ans = int(A*(min(N, B-1)/B))-A*int(min(N, B-1)/B)

print(ans)

import math

A, B, N = list(map(int, input().split()))
ans = math.floor(A * min(N, B - 1) / B) - A * math.floor(min(N, B - 1) / B)
print(ans)

A, B, N = list(map(int, input().split()))
ans = int(A * (min(N, B - 1) / B)) - A * int(min(N, B - 1) / B)
print(ans)

-import math - -ans = math.floor(A * min(N, B - 1) / B) - A * math.floor(min(N, B - 1) / B) +ans = int(A * (min(N, B - 1) / B)) - A * int(min(N, B - 1) / B)