def find(m):
  stack = []

  c = -1

  for i in range(len(m)):
    stack.append(i)

  while len(stack) > 1:
    i = stack.pop()
    j = stack.pop()

    if m[i][j] == 1:
      stack.append(j)
    else:
      stack.append(i)

  c = stack.pop()

  for i in range(len(m)):
    if i != c and (m[i][c] == 0 or m[c][i] == 1):
      return -1

  return c

matrix = [
  [0, 0, 1, 0],
  [0, 0, 1, 0],
  [0, 0, 0, 0],
  [0, 0, 1, 0]
]

print(find(matrix))

// Javascript implementation

function find(m) {
  const stack = [];

  let c = -1;

  for (let i = 0; i < m.length; i++) {
    stack.push(i);
  }

  while (stack.length > 1) {
    const i = stack.pop();
    const j = stack.pop();

    if (m[i][j] == 1) {
      stack.push(j);
    } else {
      stack.push(i);
    }
  }

  c = stack.pop()

  for (let i = 0; i < m.length; i++) {
    if (i != c && (m[i][c] == 0 || m[c][i] == 1)) {
      return -1;
    }
  }

  return c;
}

const matrix = [
  [0, 0, 1, 0],
  [0, 0, 1, 0],
  [0, 0, 0, 0],
  [0, 0, 1, 0]
];

console.log(find(matrix));