#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define ins insert
#define pq priority_queue
#define minele min_element
#define maxele max_element
#define lb lower_bound //first pos >= val
#define ub upper_bound // first pos > val
#define cnt_bit __builtin_popcount
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;


int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

const ll oo = 1e18;
const ll maxN = 1e6;

/* Author : Le Ngoc Bao Anh, 10A5, LQD High School for Gifted Student */

void maximize(int &a, int b) {
    a = max(a, b);
}

void minimize(int &a, int b) {
    a = min(a, b);
}

int res = 0;
int a[100], cnt[100];

void f(string s, int len, int x, int c, int k) {
    if(len > x) return;
    if(len == x) {
        do {
            res++;
            printf("%s ", s.c_str());
            if(res == k) return;
        } while(next_permutation(s.begin(), s.end()));
        cnt[c]--;
        return;
    }

    for(int i = max(1, c); i <= 26; i++) {
        if(cnt[i] < a[i]) {
            cnt[i]++;
            f(s + (char)(i + 'a' - 1), len + 1, x, i, k);
            if(res == k) return;
        }
    }

    cnt[c]--;
}

void f1(string s, int len, int x, int c, int k) {
    if(len > x) return;
    if(len == x) {
        do {
            res++;
            if(res == k) return;
        } while(next_permutation(s.begin(), s.end()));
        cnt[c]--;
        return;
    }

    for(int i = max(1, c); i <= 26; i++) {
        if(cnt[i] < a[i]) {
            cnt[i]++;
            f1(s + (char)(i + 'a' - 1), len + 1, x, i, k);
            if(res == k) return;
        }
    }

    cnt[c]--;
}

void solve(int x, int y, int k, int id) {

    bool okk = true;
    for(int i = 1; i <= 26; i++) {
        scanf("%d", &a[i]), a[i] = min(a[i], y);
        if(a[i] < 0) {
            okk = false;
        }
    }

    if(!okk) {
        printf("NO\n");
        return;
    }
    for(int i = 1; i <= 26; i++) cnt[i] = 0;

    res = 0;
    for(int i = x; i <= y; i++) {
        string s = "";
        if(res == k) break;
        f1(s, 0, i, 0, k);
        for(int j = 1; j <= 26; j++) cnt[j] = 0;
        if(res == k) break;
    }

    if(res < k) {
        printf("NO\n");
        return;
    } else {
        printf("YES\n");
    }

    for(int i = 1; i <= 26; i++) cnt[i] = 0;
    res = 0;
    for(int i = x; i <= y; i++) {
        string s = "";
        f(s, 0, i, 0, k);
        for(int j = 1; j <= 26; j++) cnt[j] = 0;
        if(res == k) break;
    }
    printf("\n");
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #else
    //online
    freopen("string.inp", "r", stdin);
    freopen("string.out", "w", stdout);
    #endif

    int tc = 1, ddd = 0;
    while(true) {
        //cout << "Case #" << ddd << ": ";
        int x = 0, y = 0, k = 0;
        scanf("%d %d %d", &x, &y, &k);
        if(!x) return 0;
        solve(x, y, k, ddd);
        ddd++;
    }
}