## CBOJ 2022 Spring Contest Problem 3 - Martin's Monochromatic Marbles

Points: 7 (partial)
Time limit: 1.0s
Memory limit: 512M

Author:
Problem types

Martin is a colored marble enthusiast.

He has $$3N$$ unicolored marbles ($$R$$ red ones, $$G$$ green ones, and $$B$$ blue ones), that he wants to partition into $$N$$ groups of $$3$$ marbles each. Because Martin is a chaotic individual, he calls groups with all marbles having the same color bad. Assuming he divides the marbles optimally, what is the minimum number of bad groups that Martin can form?

#### Input Specification

The first line will contain the integer $$N$$ $$(1\le N\le 10^{18})$$, the number of groups Martin wishes to form.

The second line will have three space-separated integers $$R$$, $$G$$, and $$B$$ $$(0\le R,G,B \le 3N)$$, representing the number of marbles of each color that Martin has. Note that $$R+G+B=3N$$.

#### Output Specification

An integer representing the minimum number of bad groups.

$$B=0$$

#### Sample Input 1

1
1 2 0

#### Sample Output 1

0

#### Sample Input 2

58
147 5 22

#### Sample Output 2

31