#include <bits/stdc++.h>
using namespace std;
long long powe(long long a, long long b) {
  if (b == 0) {
    return 1;
  }
  long long temp = powe(a, b / 2);
  if (b % 2 == 0) return (temp * temp) % 1000000007;
  return ((temp * temp) % 1000000007) * a % 1000000007;
}
int main() {
  string s;
  cin >> s;
  long long i, n;
  long long len = s.length();
  n = len;
  reverse(s.begin(), s.end());
  long long num = 0;
  for (i = 0; i < len; i++) {
    if (s[i] == '1') num = (num + powe(2, i)) % 1000000007;
  }
  for (i = len - 1; i >= 0; i--) {
    if (s[i] == '1') break;
  }
  if (i == -1) {
    cout << "0";
    return 0;
  } else {
    num = (powe(2, i) * num) % 1000000007;
    num = num * powe(2, (n - i - 1)) % 1000000007;
    cout << num;
  }
  return 0;
}
