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I have a c++ map declared as follows

std::map<std::string, int> wordMap= {
    { "is", 6 },
    { "the", 5 },
    { "hat", 9 },
    { "at", 6 } 
    };

I would like to know how to find the number of distinct values of int existing in wordMap. In this example, I would expect an output of 3 as i have 3 different distinct values (6,5,9).