n, a, b = map(int, input().split())
B = [-b, b]
A = [[a - b, -a - b], [-a + b, a + b]]
n -= 1
inf = 1 << 60
while n > 0:
    if n & 1:
        C = [inf] * 2
        for i in range(2):
            for j in range(2):
                C[i] = min(C[i], A[i][j] + B[j])
        B = C[:]
    C = [[inf, inf], [inf, inf]]
    for i in range(2):
        for j in range(2):
            for k in range(2):
                C[i][j] = min(C[i][j], A[i][k] + A[k][j])
    A = [row[:] for row in C]
    n >>= 1
print(min(B))