双指针
#include<bits/stdc++.h>
using namespace std;

int main()
{
    set<string> material_set;
    string str;
    int sum=0;
    while( cin>>str )
    {
        if( material_set.find( str ) != material_set.end() ) continue;
        material_set.insert(str);
        sum++;
    }
    cout<<sum<<endl;
    return 0;
}