#include <string>
#include <iostream>
using namespace std;
int main(){
string input = "some23 string 1 wit4 digits12#247<fhj";
string output;
for( size_t elem = 0; elem < input.size(); elem++ )
if( input[elem] < '0' || input[elem] > '9' )
continue;
else
output += input[elem];
cout<<"INPUT : "<<input<<endl;
cout<<"OUTPUT: "<<output<<endl;
int number = 0;
if( !output.size() )
cout<<"string not contain digits"<<endl;
else
if( sscanf(output.data(), "%d", &number) )
cout<<"NUMBER : "<<number<<endl;
else
cout<<"sscanf ERROR"<<endl;
cin.get();
return 0;
}