// yukicoder 883 ぬりえ
// 2019.9.14 bal4u

#include <stdio.h>
#include <string.h>
#include <math.h>

#if 1
int getchar_unlocked(void);
int putchar_unlocked(int c);
#define gc() getchar_unlocked()
#define pc(c) putchar_unlocked(c)
#else
#define gc() getchar()
#define pc(c) putchar(c)
#endif

int in() {   // 非負整数の入力
	int n = 0; int c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

void out(int n) { // 非負整数の表示（出力）
	int i; char b[30];

	if (!n) pc('0');
	else {
		i = 0; while (n) b[i++] = n % 10 + '0', n /= 10;
		while (i--) pc(b[i]);
	}
	pc('\n');
}
void outs(char *s) { while (*s) pc(*s++); pc('\n'); }

int N, K, M;
char A[1003][1003];

int mi(int n) { int a = (int)sqrt((double)n); if (a*a < n) a++; return a; }

int spa(int n, int k, int s) {
	int r, c, m;
	if (k*k >= n || k*(k+1) < n) return 0;
	m = k+1;
	for (r = 0; r < m && n; r++) for (c = 0; c < m && n; c++) {
		if (c != m-r-1) A[s+r][s+c] = '#', n--;
	}
	return m;
}
		
int main()
{
	int r, c;
	
	N = in(), K = in();
	memset(A, '.', sizeof(A));
	M = 0; while (N) {
		if (K*K > N) K = mi(N);
		if ((r = spa(N, K, M)) > 0) M += r, N = 0;
		else {
			for (r = 0; r < K && N; r++) for (c = 0; c < K && N; c++) {
				A[M+r][M+c] = '#', N--;
			}
			M += K;
		}
	}
	out(M);
	for (r = 0; r < M; r++) A[r][M] = 0, outs(A[r]);
	return 0;
}