#include <vector>
#include <string>
#include <iostream>
#include <sstream>
 
using namespace std;
 
void print(vector<vector<string>> s)
{
    cout << "Lists:" << endl;
    for (const auto& v : s)
    {
        cout << "List: ";
        for (const auto& i : v)
        {
            cout << i << ", ";
        }
        cout << endl;
    }
    cout << "Done" << endl;
}
 
string toStr(int i)
{
    string result;
    stringstream ss;
    ss << i;
    ss >> result;
    return result;
}
 
int main()
{
    vector<vector<string>> slist;
 
    print(slist);
 
    for (auto i = 0; i < 7; ++i)
    {
        slist.push_back(vector<string>());
        for (auto j = 0; j < 5; ++j)
        {
            slist[i].push_back("String[" + toStr(i) + "][" + toStr(j) + "]"); // also tried slist.back().push_back("S");
        }
    }
 
    print(slist);
}

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