def f(M):
    l=[]
    for i in range(1,M.getNoLines):
        for j in range(1,M.getNoColumns):
            if M.get(i, j)!=0:
                if M.get(i-1,j)!=M.get(i,j) and M.get(i,j-1)!=M.get(i,j):
                    el=getCenter(M,i,j)
                    if el not in l:
                        l.append(el)
    return l


def getCenter(M,i,j):
    i1=i
    j1=j
    while M.get(i,j)==M(i1,j):
        i1+=1
    i1-=1
     while M.get(i, j) == M(i, j1):
        j1 += 1
    j1 -= 1
    return (int(float(i1-i)/2+i),int(float(j1-j)/2+j)