A king goes to an island, where there are 5823 people who always tell the truth and 8723 who always lie.
The king is special guest for the party celebrating 2053 year.
On the party, liars and truth tellers dance in couples (everyone can dance with everyone), some people leave the dance, others join and some don't even participate in the dances as they are not dance lovers.
After the party, the king asked everyone who had danced on the party, how many truth tellers did he dance with and put the numbers into his diary. Surprisingly, when he checked his diary later on, he found out he had all the numbers from 0 to 956 typed in uniquely.
How many truth tellers danced on the party, assuming everyone knows who is truth teller and who is liar?