876A - Trip For Meal - CodeForces Solution

n = int(input())
a = int(input())
b = int(input())
c = int(input())
cnt = 0
mi = min(a, b)
if n == 1:
    pass
else:
    if mi > c:
        cnt = mi + c * (n-2)
    else:
        cnt = mi * (n-1)
print(cnt)