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

ans = A * (N - 1) + N * B
u = (N + 1) // 2
v = N
ans1 = ans - 2 * A * min(u,N - u) - 2 * u * B
ans2 = ans - 2 * N * B
print(min(ans1,ans2))