我也来

#include<bits/stdc++.h>
using namespace std;
string s,s1;
int m;
int main()
{
    cin>>s1>>s>>m;
    for(int i=1;i<=s.size();i++)
    { 
        cout<<s[i-1];
        if(i==m)
        {
            cout<<s1;
        }
    }
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
    string s1,s2;
    cin >> s2 >> s1;
    int y;
    cin >> y;
    for (int i = 1;i <= s1.length();i++)
    {
        cout << s1[i - 1];
        if (i == y) cout << s2;
    }
}