Codeforces876A-Trip For Meal

A. Trip For Meal

time limit per test

memory limit per test

input

output

Winnie-the-Pooh likes honey very much! That is why he decided to visit his friends. Winnie has got three best friends: Rabbit, Owl and Eeyore, each of them lives in his own house. There are winding paths between each pair of houses. The length of a path between Rabbit's and Owl's houses is a meters, between Rabbit's and Eeyore's house is b meters, between Owl's and Eeyore's house is cmeters.

For enjoying his life and singing merry songs Winnie-the-Pooh should have a meal n

Winnie-the-Pooh does not like physical activity. He wants to have a meal n

Input

First line contains an integer n (1 ≤ n ≤ 100) — number of visits.

Second line contains an integer a (1 ≤ a ≤ 100) — distance between Rabbit's and Owl's houses.

Third line contains an integer b (1 ≤ b ≤ 100) — distance between Rabbit's and Eeyore's houses.

Fourth line contains an integer c (1 ≤ c ≤ 100) — distance between Owl's and Eeyore's houses.

Output

Output one number — minimum distance in meters Winnie must go through to have a meal n

Examples

input

3 2 3 1

output

3

input

1 2 3 5

output

0

Note

In the first test case the optimal path for Winnie is the following: first have a meal in Rabbit's house, then in Owl's house, then in Eeyore's house. Thus he will pass the distance 2 + 1 = 3.

In the second test case Winnie has a meal in Rabbit's house and that is for him. So he doesn't have to walk anywhere at all.

题解：Div2T1应该比较简单，直接模拟就可以了。

Code：

var n,a,b,c,now,i,x,ans,p:longint;
begin
   readln(n);
   readln(a);
   readln(b);
   readln(c);
   now:=1;
   for i:=2 to n do
   begin
      if now=1 then
      begin
         if a<b then begin x:=a;p:=2;end
         else begin x:=b;p:=3;end;
      end;
      if now=2 then
      begin
         if a<c then begin x:=a;p:=1;end
         else begin x:=c;p:=3;end;
      end;
      if now=3 then
      begin
         if b<c then begin x:=b;p:=1;end
         else begin x:=c;p:=2;end;
      end;
      ans:=ans+x;
      now:=p;
   end;
   writeln(ans);
end.