process.stdin.resume();
process.stdin.setEncoding('utf8');
 
// your code goes here
var readline = require("readline");
 
function uniqWord(callback) {
    var seen = {};
    return function (line) {
        var words = line.match(/\S+/g) || [];
        words.forEach(function(word) {
            if (word in seen) return;
            seen[word] = true;
            callback(word);
        });
    }
 }
 
function main() {
    var rl = readline.createInterface(process.stdin, process.stdout);
 
    rl.on('line', uniqWord(function(word) {
        console.log(word);
    }));
}
main()

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

YWFhIGJiYiBjY2MgYmJiIGFhYQpkZGQgY2NjIGVlZSBhYWEgZmZmCmZmZiBjY2MgYWFhIGdnZyBlZWU=

aaa bbb ccc bbb aaa
ddd ccc eee aaa fff
fff ccc aaa ggg eee