Buggy python submission (verdict: Runtime Error):
while True:
    h,w=map(int, input().split())
    if h==w== 0:break
    if h%2==1:
        print('#.'*(w/2) + '\n')
    else:
        print('.#'*(w/2) + '\n')

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while True:
    h,w=map(int, input().split())
    if h==w== 0:break
    for x in (h+1):
        if h%2==1:print('#.'*(w//2) + '\n')
        else:print('.#'*(w//2) + '\n')

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while True:
    h,w=map(int, input().split())
    if h==w== 0:break
    for x in (h):
        if h%2==1:print('#.'*(w//2) + '\n')
        else:print('.#'*(w//2) + '\n')

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(1,h+1):
        for x in range(1,w+1):
        if ((x+y)%2)==0:prnt('#',end())
        else print('.',end())
    print('\n')

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while True:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(1,w+1):
            if ((x+y)%2)==0:prnt('#',end())
            else print('.',end())
        print()
    print()

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while True:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(1,w+1):
            if (x+y)%2==0:prnt('#',end='')
            else print('.',end='')
        print()
    print()

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while True:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:prnt('#',end='')
            else print('.',end='')
        print()
    print()

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()

Buggy python submission (verdict: Runtime Error):
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            else print('.',end='')
        print()
    print()

Fixed submission:
while 1:
    h,w = map(int, input().split())
    if h==w==0:break
    for y in range(h):
        for x in range(w):
            if (x+y)%2==0:print('#',end='')
            if (x+y)%2==1: print('.',end='')
        print()
    print()