Class 20.08.13

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <bitset>
#include <iostream>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <algorithm>
using namespace std;

int n, r, c, m, w;
bool u[110][110];

int main() {
    freopen("class.in", "r", stdin);
    freopen("class.out", "w", stdout);
    scanf("%d%d%d", &n, &r, &c);
    m = min(r, c);
    if (2 * m - 1 <= n)
        w = m;
    else
        w = (n - 1) / 2 + 1;

    printf("%d\n", w);
    for (int j = 0; j < w; j++) {
        u[0][j] = 1;
        n--;
    }
    for (int i = 1; i < w; i++) {
        u[i][0] = 1;
        n--;
    }
    for (int i = 0; i < r; i++) {
        for (int j = 0; j < c; j++) {
            if (u[i][j] || !n)
                continue;
            u[i][j] = 1;
            n--;
        }
    }

    for (int i = 0; i < r; i++) {
        for (int j = 0; j < c; j++)
            printf("%c", u[i][j] ?  '#' : '.');
        printf("\n");
    }
    return 0;
}