/*
        Author       :  Jan
        Problem Name :
        Algorithm    :
        Complexity   :
    */

    #include <set>
    #include <map>
    #include <list>
    #include <cmath>
    #include <ctime>
    #include <deque>
    #include <queue>
    #include <stack>
    #include <cctype>
    #include <cstdio>
    #include <string>
    #include <vector>
    #include <cassert>
    #include <cstdlib>
    #include <cstring>
    #include <sstream>
    #include <iostream>
    #include <algorithm>

    using namespace std;

    const int NN = 50;
    const int MAX = 200;

    int deg[MAX], adj[MAX][MAX], cap[MAX][MAX], Cap[MAX][MAX], q[MAX];
    int dinic( int n, int s, int t ) {
        int prev[MAX], u, v, i, j, z, flow = 0, qh, qt, inc;
        for( i = 0; i < n; i++ ) {
            deg[i] = 0;
            for( j = 0; j < n; j++ ) {
                Cap[i][j] = cap[i][j];
                if( cap[i][j] || cap[j][i] ) adj[i][ deg[i]++ ] = j;
            }
        }
        while(1) {
            memset( prev, -1, sizeof( prev ) );
            qh = qt = 0;
            prev[s] = -2;
            q[qt++] = s;
            while( qt != qh && prev[t] == -1 ) {
                u = q[qh++];
                for(i = 0; i < deg[u]; i++) {
                    v = adj[u][i];
                    if( prev[v] == -1 && cap[u][v] ) {
                        prev[v] = u;
                        q[qt++] = v;
                    }
                }
            }
            if(prev[t] == -1) break;
            for(z = 0; z < n; z++) if( prev[z] !=- 1 && cap[z][t] ) {
                inc = cap[z][t];
                for( v = z, u = prev[v]; u >= 0; v = u, u=prev[v]) inc = min( inc, cap[u][v] );
                if( !inc ) continue;
                cap[z][t] -= inc;
                cap[t][z] += inc;
                for(v=z, u = prev[v]; u >= 0; v = u, u = prev[v]) {
                    cap[u][v] -= inc;
                    cap[v][u] += inc;
                }
                flow += inc;
            }
        }
        return flow;
    }

    int denoteInfo( int k ) {
        if( k <= 26 ) return k + 96;
        return k - 26 + 64;
    }

    char res[10005][30];

    int main() {
        freopen("a1.in", "r", stdin);
        freopen("a1.ans", "w", stdout);

        double cl = clock();

        int cases, caseno = 0;
        scanf("%d", &cases);
        while( cases-- ) {
            int n, t, c, e, a[NN+5], d[NN+5], f[NN+5], I[2*NN+5][2], K = 0, needFlow = 0;
            set <int> S;
            scanf("%d %d %d %d", &n, &t, &c, &e);
            assert(1 <= n && n <= 50 && 1 <= t && t <= 5 && 1 <= c && c <= 5 && 2 <= e && e <= 10000);
            for( int i = 1; i <= n; i++ ) {
                scanf("%d %d %d", &a[i], &d[i], &f[i]);
                assert( 1 <= a[i] && a[i] < d[i] && 1 <= f[i] && f[i] <= d[i] - a[i] );
                S.insert( a[i] );
                S.insert( d[i] );
            }
            for( set <int>::iterator s = S.begin(), s1; s != S.end(); s++ ) {
                s1 = s;
                s1++;
                if( s1 == S.end() ) break;
                I[++K][0] = *s;
                I[K][1] = (*s1) - 1;
            }
            memset( cap, 0, sizeof(cap) );
            for( int i = 1; i <= n; i++ ) {
                cap[0][i] = f[i];
                needFlow += f[i];
                for( int j = 1; j <= K; j++ ) if( a[i] <= I[j][0] && d[i] > I[j][1] ) cap[i][n+j] = I[j][1] - I[j][0] + 1;
            }
            for( int j = 1; j <= K; j++ ) cap[n+j][n+K+1] = ( I[j][1] - I[j][0] + 1 ) * t * c;
            printf("Case %d: ", ++caseno);
            if( needFlow != dinic( n+K+2, 0, n+K+1 ) ) {
                puts("No");
                continue;
            }
            puts("Yes");

            for( int i = 0; i < e - 1; i++ ) {
                for( int j = 0; j < t*c; j++ ) res[i][j] = '.';
                res[i][t*c] = 0;
            }

            for( int j = 1; j <= K; j++ ) {
                priority_queue < pair <int, int> > Q, R;
                for( int i = 1; i <= n; i++ ) if( Cap[i][j+n] > cap[i][j+n] ) Q.push( make_pair( Cap[i][j+n] - cap[i][j+n], i ) );
                for( int k = I[j][0]; k <= I[j][1]; k++ ) R.push( make_pair( t*c, k ) );

                while( !Q.empty() ) {
                    pair <int, int> u = Q.top(); Q.pop();
                    stack < pair <int, int> > temp;
                    for( int y = 0; y < u.first; y++ ) {
                        pair <int, int> v = R.top(); R.pop();
                        res[v.second-1][--v.first] = denoteInfo( u.second );
                        if( v.first ) temp.push( v );
                    }
                    while( !temp.empty() ) {
                        R.push( temp.top() );
                        temp.pop();
                    }
                }
            }
            for( int i = 0; i < e - 1; i++ ) {
                for( int j = 0; j < t; j++ ) {
                    for( int k = 0; k < c; k++ ) putchar( res[i][j*c+k] );
                    if( j < t - 1 ) putchar('|');
                }
                puts("");
            }
        }

        cl = clock() - cl;
        fprintf(stderr, "Total Execution Time = %lf seconds\n", cl / CLOCKS_PER_SEC);

        return 0;
    }