N = int(input())
C,V = map(int,input().split())

INF = (1<<30)

dp = [INF]*(N+2)
def f(x):
    return min(x,N+1)

dp[1]=0
for i in range(1,N+1):
    
    for j in range(2*i,N+i,i):
        dp[f(j)] = min(dp[f(j)],dp[i] + (j-i)//i*V + C)
    
    cnt = 1
    j = i
    while j<N:
        dp[f(2*j)] = min(dp[f(2*j)],dp[i]+cnt*(C+V))
        cnt += 1
        j *= 2
        
ans = min(dp[N],dp[N+1])
print(ans)