def gvt(): #fonction renommée depuis ...

  b = 20

  while b>0:

    x, y = randint(0,14),randint(0,9)

    if m[x][y]!=999:

      m[x][y]=999

      b-=1

      for p in range(max(0,x-1),min(15,x+2)):

        for q in range(max(0,y-1),min(10,y+2)):

          if m[p][q]!=999:m[p][q]+=100