#include <bits/stdc++.h>
template <class T>
inline T bigmod(T p, T e, T M) {
  long long int ret = 1;
  for (; e > 0; e >>= 1) {
    if (e & 1) ret = (ret * p) % M;
    p = (p * p) % M;
  }
  return (T)ret;
}
template <class T>
inline T gcd(T a, T b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
template <class T>
inline T modinverse(T a, T M) {
  return bigmod(a, M - 2, M);
}
using namespace std;
vector<int> primeNumber;
void sieve(int n) {
  bool mark[1000002];
  memset(mark, (true), sizeof(mark));
  int i, j, limit = sqrt(n * 1.) + 2;
  primeNumber.emplace_back(2);
  for (i = 3; i <= n; i += 2) {
    if (mark[i] == false) continue;
    primeNumber.emplace_back(i);
    if (i <= limit) {
      for (j = i * i; j <= n; j += i * 2) mark[j] = false;
    }
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int testCase = 1;
  for (int tes = 1; tes <= testCase; tes++) {
    string s;
    cin >> s;
    long long int ans = 0;
    int n = s.size();
    for (int i = 0; i < n; i++) {
      if (s[i] == '1') {
        ans += bigmod((long long int)2, (long long int)n - i - 1,
                      (long long int)1000000007);
        ans %= 1000000007;
      }
    }
    ans *= bigmod((long long int)2, (long long int)n - 1,
                  (long long int)1000000007);
    cout << ans % 1000000007 << endl;
  }
}
