#include <string>
#include <iostream>
#include <iomanip>
#include <algorithm>
using namespace std;
int main(int argc, const char * argv[])
{
int total = 0, bad = 0;
string s = "0123456789";
do {
if (s[0] < '3' || s[1] < '3' || s[2] < '3' || s[3] < '3') bad++;
total++;
} while(next_permutation(s.begin(),s.end()));
cout << double(bad)/total << endl;
}
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