def problema1(A,x,y,c):
#@param A:picture
#@param x:integer
#@param y:integer
#@param c:color
  if x<0 or x>=getWidth(A) or y<0 or y>=getHeight(A):
    print "input non valido"
    return -1
  else:
    for i in range(0,getWidth(A)-x):
      if y+i<getHeight(A):
        setColor(getPixel(A,i+x,i+y),c)
    repaint(A)
def problema2(M,x,y):
#@param M:matrix
#@param x:integer
#@param y:integer
#@param c:color
  if x<0 or x>=len(M[y]) or y<0 or y>=len(M):
    print "input non valido"
    return -1
  else:
    for i in range(0,len(M)-y):
      if x+i<len(M[y]):
        M[y+i][x+i]=0