#include <iostream>
#include <string>
using namespace std;
int main()
{
	setlocale(LC_ALL, "ru");

	int k = 0;
	char res[255]{};
	char str[255]="h2h5h1h6k7;3m/2;6[/2[51]]5";

	cout << "вот ваша строка:\n"<<str << endl;



	for (int i = 0; i < strlen(str); i++)
	{
		if (47 < (int)str[i] && (int)str[i] < 58)
		{
			res[k] = str[i];
			res[k + 1] = '\0';
			k++;
		}
	}
	cout << "готово: "<<res << endl;


}