#include <bits/stdc++.h>
const int MaxN = 105;
template <class t>
inline void read(t &s) {
  s = 0;
  register int f = 1;
  register char c = getchar();
  while (!isdigit(c)) {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (isdigit(c)) s = (s << 3) + (s << 1) + (c ^ 48), c = getchar();
  s *= f;
  return;
}
template <class t, class... A>
inline void read(t &x, A &...a) {
  read(x);
  read(a...);
}
template <class t>
inline void write(t x) {
  if (x < 0) putchar('-'), x = -x;
  int buf[21], top = 0;
  while (x) buf[++top] = x % 10, x /= 10;
  if (!top) buf[++top] = 0;
  while (top) putchar(buf[top--] ^ '0');
  return;
}
inline void setIn(std::string s) {
  freopen(s.c_str(), "r", stdin);
  return;
}
inline void setOut(std::string s) {
  freopen(s.c_str(), "w", stdout);
  return;
}
inline void setIO(std::string s = "") {
  setIn(s + ".in");
  setOut(s + ".out");
  return;
}
template <class t>
inline bool checkmin(t &x, t y) {
  if (x > y) {
    x = y;
    return 1;
  }
  return 0;
}
template <class t>
inline bool checkmax(t &x, t y) {
  if (x < y) {
    x = y;
    return 1;
  }
  return 0;
}
inline int lowbit(int x) { return x & (-x); }
std::vector<int> E[MaxN], cur;
char s[MaxN][MaxN];
int ovr[MaxN], a[MaxN], n;
signed main(void) {
  read(n);
  for (int i = 1; i <= n; ++i) std::scanf("%s", s[i] + 1);
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= n; ++j)
      if (s[i][j] == '1') E[i].push_back(j);
  for (int i = 1; i <= n; ++i) read(a[i]);
  std::vector<int> ans;
  while (true) {
    register int pos = -1;
    for (int i = 1; i <= n; ++i)
      if (!a[i] && !ovr[i]) {
        pos = i;
        break;
      }
    if (!~pos) break;
    for (auto v : E[pos]) --a[v];
    ovr[pos] = 1, ans.push_back(pos);
  }
  for (int i = 1; i <= n; ++i)
    if (!a[i]) return std::puts("-1"), 0;
  write((int)ans.size()), std::puts("");
  for (auto i : ans) write(i), std::putchar(32);
  std::puts("");
  return 0;
}
