#include<iostream>
#include <cmath>
#include <iostream>
#include <iterator>
#include <map>
#include <set>
#include <string>
#include <vector>
#include <algorithm>
#include <stack>

#define int long long
#define pb push_back

using namespace std;

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    string s;
    cin >> s;
    stack<int> st;
    for (int i = 0; i < s.size(); i++) {
        if (s[i] == '(' || s[i] == '[' || s[i] == '{') {
            st.push(s[i]);
        }
        if (s[i] == ')' || s[i] == ']' || s[i] == '}') {
            if (st.top() == s[i]) {
                st.pop();
            } else {
                cout << "no";
                return 0;
            }
        }
    }
    if (st.size() == 0) {
        cout << "yes";
    } else {
        cout << "no";
    }
}