Buggy python submission (verdict: Runtime Error):
import numpy as np

def main():
    H, W = [int(i) for i in input().split()]
    N = int(input())
    a = [int(i) for i in input().split()]
    
    color_ar = np.zeros((H, W), dtype=np.int32)
    #print(color_ar)
    
    y = 0
    x = 1
    
    for i in range(N):
        t = a[i]
        while t > 0:
            if(np.count_nonzero(color_ar) == 0):
                color_ar[0,0] = i + 1
            else:
                color_ar[y,x] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
            t -= 1
            
    #print(color_ar)
    for y in range(H):
        for x in range(W):
            print(color_ar[y,x], end="")
            if(x < W - 1):
                print(" ",end="")
        if(y < H -1 ):
            print("")
            
if __name__=="__main__":
    main()

Fixed submission:
import numpy as np

def main():
    H, W = [int(i) for i in input().split()]
    N = int(input())
    a = [int(i) for i in input().split()]
    
    color_ar = np.zeros((H, W), dtype=np.int32)
    #print(color_ar)
    
    y = 0
    x = 0
    
    for i in range(N):
        t = a[i]
        while t > 0:
            if(np.count_nonzero(color_ar) == 0):
                color_ar[0,0] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
                    
            else:
                color_ar[y,x] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
            t -= 1
            
    #print(color_ar)
    for y in range(H):
        for x in range(W):
            print(color_ar[y,x], end="")
            if(x < W - 1):
                print(" ",end="")
        if(y < H - 1 ):
            print("")
            
if __name__=="__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np

def main():
    H, W = [int(i) for i in input().split()]
    N = int(input())
    a = [int(i) for i in input().split()]
    
    color_ar = np.zeros((H, W), dtype=np.int32)
    #print(color_ar)
    
    y = 0
    x = 1
    
    for i in range(N):
        t = a[i]
        while t > 0:
            if(np.count_nonzero(color_ar) == 0):
                color_ar[0,0] = i + 1
            else:
                color_ar[y,x] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
            t -= 1
            
    #print(color_ar)
    for y in range(H):
        for x in range(W):
            print(color_ar[y,x], end="")
        if(y < H -1 ):
            print("\n")
            
if __name__=="__main__":
    main()

Fixed submission:
import numpy as np

def main():
    H, W = [int(i) for i in input().split()]
    N = int(input())
    a = [int(i) for i in input().split()]
    
    color_ar = np.zeros((H, W), dtype=np.int32)
    #print(color_ar)
    
    y = 0
    x = 0
    
    for i in range(N):
        t = a[i]
        while t > 0:
            if(np.count_nonzero(color_ar) == 0):
                color_ar[0,0] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
                    
            else:
                color_ar[y,x] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
            t -= 1
            
    #print(color_ar)
    for y in range(H):
        for x in range(W):
            print(color_ar[y,x], end="")
            if(x < W - 1):
                print(" ",end="")
        if(y < H - 1 ):
            print("")
            
if __name__=="__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np

def main():
    H, W = [int(i) for i in input().split()]
    N = int(input())
    a = [int(i) for i in input().split()]
    
    color_ar = np.zeros((H, W), dtype=np.int32)
    #print(color_ar)
    
    y = 0
    x = 1
    
    for i in range(N):
        t = a[i]
        while t > 0:
            if(np.count_nonzero(color_ar) == 0):
                color_ar[0,0] = i + 1
            else:
                color_ar[y,x] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
            t -= 1
            
    #print(color_ar)
    for y in range(H):
        for x in range(W):
            print(color_ar[y,x], end="")
        print("\n")
            
if __name__=="__main__":
    main()

Fixed submission:
import numpy as np

def main():
    H, W = [int(i) for i in input().split()]
    N = int(input())
    a = [int(i) for i in input().split()]
    
    color_ar = np.zeros((H, W), dtype=np.int32)
    #print(color_ar)
    
    y = 0
    x = 0
    
    for i in range(N):
        t = a[i]
        while t > 0:
            if(np.count_nonzero(color_ar) == 0):
                color_ar[0,0] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
                    
            else:
                color_ar[y,x] = i + 1
                if((y + 1) % 2 == 0):
                    x -= 1
                else:
                    x += 1
                
                if((x < 0) or (x >= W)):
                    y += 1
                    if(x < 0):
                        x = 0
                    else:
                        x = W - 1
            t -= 1
            
    #print(color_ar)
    for y in range(H):
        for x in range(W):
            print(color_ar[y,x], end="")
            if(x < W - 1):
                print(" ",end="")
        if(y < H - 1 ):
            print("")
            
if __name__=="__main__":
    main()