import sys 
input = sys.stdin.buffer.readline
def main():
    d = int(input()); INF = float("inf")
    a,b = map(int,input().split())
    ans = INF
    for x in range(d+1):
        cost = x*a + abs(d-x)*b
        ans = min(ans,cost)
    print(ans)

if __name__ == '__main__':
    main()