#include <bits/stdc++.h>
using namespace std;
long long n, i, j, ans = 0;
long long a, b;
const long long M = (long long)1E9 + 7;
long long power(long long x, long long y) {
  long long res = 1;
  x %= M;
  while (y) {
    if (y % 2) res = (res * x) % M;
    y = y >> 1;
    x = (x * x) % M;
  }
  return res % M;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string s;
  cin >> s;
  b = power(2LL, (long long)s.length() - 1);
  long long x = 1;
  for (i = (long long)s.length() - 1; i >= 0; i--) {
    if (s[i] == '1') a += x;
    x *= 2;
    if (x > M) x %= M;
    a %= M;
  }
  cout << (a * b) % M;
}
