Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.

void solve()
{
    char s1[100], s2[100];
    scanf("%s%s", s1, s2);
    strcat(s1, s2);
    printf("%s", s1 );

 }