乱写的，觉得肯定错，结果过了。。

#include <bits/stdc++.h>
using namespace std;

#define int long long
const int N = 3e5 + 5;

int n, res, flg;
char a[N];
map<char, int> vis;

signed main() {
    cin >> (a + 1);
    int lena = strlen(a + 1);
    for (int i = 1; i <= lena; i++) {
        if (a[i] >= 'a' && a[i] <= 'z') {
            if (vis[a[i]]) flg = 1;
            vis[a[i]] = 1;
        }
        if (a[i] == ')') vis.clear();
    }
    if (flg) puts("No");
    else puts("Yes");
}