#include <bits/stdc++.h>
using namespace std;
long long n, m, i, j, k, x, y, tmp, ans;
char s[1005];
long long Multi(long long x) {
  long long ans = 1, a = 2;
  while (x > 0) {
    if (x & 1) ans = (ans * a) % 1000000007;
    x >>= 1;
    a = (a * a) % 1000000007;
  }
  return ans % 1000000007;
}
int main() {
  scanf("%s", &s);
  n = strlen(s);
  ans = 0;
  tmp = 0;
  for (i = n - 1; i >= 0; i--) {
    x = n - 1 - i;
    y = s[i] - '0';
    if (!y)
      continue;
    else
      tmp = (tmp + (Multi(x) % 1000000007)) % 1000000007;
  }
  x = tmp;
  y = x;
  if (x == 0) {
    printf("0\n");
    return 0;
  }
  {
    tmp = 0;
    for (i = n - 1; i >= 0; i--) {
      if (s[i] == '1') {
        tmp = n - 1 - i;
        break;
      }
    }
    y = Multi(n - 1) % 1000000007;
    ans = (y * x) % 1000000007;
    printf("%I64d\n", ans);
  }
  return 0;
}
