#include
#include
using std::string;
main(void)
{
string s1 = "abcdefghijk", s2 = "1234567890", s3,s4,s5;
s3=s1+s2;
cout << s3 <
if (s4==s3)
cout << " s4==s3 is true\n";
return(0);
}
abcdefghijk1234567890
s4==s3 is true