#include <stdio.h>
#include <vector>
#include <algorithm>
#include <math.h>
using namespace std;

#define MAX_N 220000

#define INPUT_FILE "fixdna.in"
#define OUTPUT_FILE "fixdna.out"

int n, k, t;
char original[MAX_N];
char output[MAX_N];

int distances[50][50];

class XX {
public:
    int index;
    int weight;

    XX() {
        index = 0;
        weight = 0;
    }

    XX(int _index, int _weight) {
        index = _index;
        weight = _weight;
    }

    bool operator < (const XX &a) const {
        if (weight == a.weight) {
            return index < a.index;
        }
        return weight > a.weight;
    }
};

void readInput() {
    FILE *f = fopen(INPUT_FILE, "r");
    fscanf(f, "%d%d%d", &n, &k, &t);
    fscanf(f, "%s", original);
    fscanf(f, "%s", output);

    for (int i = 0; i < k; i++) {
        for (int j = 0; j < k; j++) {
            fscanf(f, "%d", &distances[i][j]);
        }
    }

    fclose(f);
}

int charDistance(char a, char b) {
    return distances[a - 'a'][b - 'a'];
}

int distance(int n, char *original, char *test) {
    int d = 0;
    for (int i = 0; i < n; i++) {
        d += charDistance(original[i], test[i]);
    }
    return d;
}

vector<XX> tt;

void solve() {
    //printf("n = %d\n", n);
    //printf("k = %d\n", k);
    //printf("t = %d\n", t);

    //printf("original = %s\n", original);
    //printf("output = %s\n", output);

    int dst = distance(n, output, original);
    //printf("distance = %d\n", dst);

    tt.clear();
    for (int i = 0; i < n; i++) {
        //printf("%c %c -> %d\n", original[i], output[i], charDistance(original[i], output[i]));
        if (charDistance(original[i], output[i]) > 0) {
            tt.push_back(XX(i, charDistance(original[i], output[i])));
        }
    }

    sort(tt.begin(), tt.end());
    for (int i = 0; i < tt.size(); i++) {
        //printf("%d %d\n", tt[i].index, tt[i].weight);
    }
}

void writeOutput() {
    FILE *f = fopen(OUTPUT_FILE, "w");

    int ttt = tt.size();
    int kk = min(t / 2, ttt);

    fprintf(f, "%d\n", 2 * kk);
    for (int i = 0; i < kk; i++) {
        fprintf(f, "3 %d\n", tt[i].index);
        fprintf(f, "4 %d %c\n", tt[i].index, original[i]);
    }

    fclose(f);
}

int main() {
    readInput();
    solve();
    writeOutput();
    return 0;
}