#include <bits/stdc++.h>
using namespace std;
template <typename T>
void out(T x) {
  cout << x << endl;
  exit(0);
}
const int maxn = 4e5 + 5;
const long long mod = 1000000007;
string s;
long long pow4[105];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  pow4[0] = 1;
  for (int i = 1; i < 105; i++) {
    pow4[i] = 4 * pow4[i - 1];
    pow4[i] %= mod;
  }
  cin >> s;
  reverse(s.begin(), s.end());
  int n = s.length();
  long long cur = 0;
  if (s[0] == '1') cur = 1;
  for (int i = 1; i < n; i++) {
    if (s[i] == '0') {
      cur *= 2;
      cur %= mod;
    } else {
      cur *= 2;
      cur %= mod;
      cur += pow4[i];
      cur %= mod;
    }
  }
  cout << cur << endl;
  return 0;
}
