// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(String S) {
        // write your code in Java SE 8
    }
}

// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(String S) {
        // write your code in Java SE 8
        Stack<Character> stack = new Stack<>();

        if (S.length() <= 1) {
            return 0;
        }
        for (int i=0; i<S.length(); i++) {
            char chr = S.charAt(i);
            if (chr == '(') {
                stack.push(chr);
            } else {
                if (chr == ')' && stack.isEmpty()) {
                    return 0;
                }
                if (stack.pop() == '(' && chr != ')') {
                    return 0;
                }
            }
        }
        return 1;
    }
}

// you can also use imports, for example:
// import java.util.*;
import java.util.Stack;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(String S) {
        // write your code in Java SE 8
        Stack<Character> stack = new Stack<>();

        if (S.length() <= 1) {
            return 0;
        }
        for (int i=0; i<S.length(); i++) {
            char chr = S.charAt(i);
            if (chr == '(') {
                stack.push(chr);
            } else {
                if (chr == ')' && stack.isEmpty()) {
                    return 0;
                }
                if (stack.pop() == '(' && chr != ')') {
                    return 0;
                }
            }
        }
        return 1;
    }
}

// you can also use imports, for example:
// import java.util.*;
import java.util.Stack;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(String S) {
        // write your code in Java SE 8
        Stack<Character> stack = new Stack<>();

        if (S.length() <= 1) {
            return 0;
        }
        for (int i=0; i<S.length(); i++) {
            char chr = S.charAt(i);
            if (chr == '(') {
                stack.push(chr);
            } else {
                if (chr == ')' && stack.isEmpty()) {
                    return 0;
                }
                if (stack.pop() == '(' && chr != ')') {
                    return 0;
                }
            }
        }
        return 1;
    }
}