#include <bits/stdc++.h>
using namespace std;
long long MOD = 1e9 + 7;
long long FastPower(long long x, long long y) {
  long long res = 1;
  x = x % MOD;
  while (y > 0) {
    if (y & 1) res = (res * x) % MOD;
    y = y >> 1;
    x = (x * x) % MOD;
  }
  return res;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, k;
  string s;
  cin >> s;
  n = s.size();
  long long x = 0, y = 0;
  y = FastPower(2, n - 1);
  for (int i = 0, j = n - 1; i < n; i++, j--) {
    if (s[j] == '1') {
      x += FastPower(2, i);
      x %= MOD;
    }
  }
  cout << (x * y) % MOD;
  return 0;
}
