#include<stdio.h>
 
int main(void)
{
    int H, W, i, j, f;
    for (;;) {
        scanf("%d %d", &H, &W);
        if (H == 0 && W ==0) exit(0);
        f=0;
        for (i=1; i<=H; i++) {
            for (j=1; j<=W; j++) {
                printf(f==0?"#":"i");
                f ^= 1;
            }
            printf("\n");
        }
        printf("\n");
    }
}


