import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  try {
    for (; ; ) {
      const N = readInt();
      const S = readToken();
      const T = readToken();
      
      auto A = new int[N];
      auto B = new int[N];
      foreach (i; 0 .. N) {
        A[i] = (S[i] - '0') << 1 | (S[N + i] - '0');
        B[i] = (T[i] - '0') << 1 | (T[N + i] - '0');
      }
      bool ok = true;
      foreach (i; 0 .. N) {
        ok = ok && ((A[i] == 0) == (B[i] == 0));
      }
      if (ok) {
        int[] ans;
        foreach (i; 0 .. N) {
          void doIt(int[] ss) {
            foreach (s; ss) {
              if (s == 0) {
                ans ~= i;
              } else {
                ans ~= i + 1;
              }
            }
          }
          if (A[i] == 1 && B[i] == 2) doIt([0, 1]);
          if (A[i] == 1 && B[i] == 3) doIt([1, 0]);
          if (A[i] == 2 && B[i] == 1) doIt([1, 0]);
          if (A[i] == 2 && B[i] == 3) doIt([0, 1]);
          if (A[i] == 3 && B[i] == 1) doIt([0, 1]);
          if (A[i] == 3 && B[i] == 2) doIt([1, 0]);
        }
        
        writeln(ans.length);
        foreach (j; ans) {
          writeln(j);
        }
        
        debug {
          uint[] xs = S.map!(c => (c - '0')).array;
          uint[] ys = T.map!(c => (c - '0')).array;
          foreach (j; ans) {
            foreach (k; 0 .. N) {
              xs[(j + k) % $] ^= xs[(j + k + N) % $];
            }
            writeln(xs);
          }
          assert(xs == ys);
        }
      } else {
        writeln(-1);
      }
    }
  } catch (EOFException e) {
  }
}