#include <bits/stdc++.h>
using namespace std;
long long p(long long N, long long P) {
  if (!P) return 1;
  if (P & 1) return (N * p(N, P - 1)) % 1000000007;
  long long r = p(N, P / 2);
  return (r * r) % 1000000007;
}
char x[110];
int main() {
  char c = 0;
  long long n = 0;
  while ((c = getchar()) != '\n') {
    n++;
    x[n] = c;
  }
  long long size = p(2, n), acc = 1, count = 0, two = p(2, 1000000007 - 2);
  for (int i = 1; i <= n; i++) {
    if (x[i] == '1') {
      count = (count + (((acc * ((size * two) % 1000000007)) % 1000000007) *
                        ((size * two) % 1000000007)) %
                           1000000007) %
              1000000007;
    }
    acc = (acc * 2) % 1000000007;
    size = (size * two) % 1000000007;
  }
  cout << count << endl;
  return 0;
}
