What will be the output of the following C++ code?

#include <iostream>
#include <map> 
using namespace std;
int main ()
{
    multimap<char, int> mymultimap;
    mymultimap.insert(make_pair('x', 100));
    mymultimap.insert(make_pair('y', 200));
    mymultimap.insert(make_pair('y', 350));
    mymultimap.insert(make_pair('z', 500));
    cout << mymultimap.size() << '\n';
    return 0;
}