#include <iostream>
#include <vector>
#include <map>
#include <cstdio>
#include <sstream>

int main() {
    std::map< std::vector<std::string>, int> m;
    m[{"hello","world"}]=1;
    m[{"momma"}]=2;
    m[{"a","b"}]=3;
    m[{"momma","zz"}]=4;
    m[{"zz","momma","b"}]=5;
    m[{"zz","momma","a"}]=6;
    for(auto &[k,v]: m)
    {
        std::ostringstream strm;
        for(auto &kv: k)
            strm << ((&kv == &*k.begin())?"[":",") << kv;
        strm << "]";
        fprintf(stderr,"k.size %ld, k %s, v %d\n", k.size(), strm.str().c_str(), v);
    }
    return 0;
}