As the players enter the hall, they are given envelopes. The young men are given blue envelopes (or something similar), and the young women are given white ones. In all the envelopes there are halves of picture cards or post cards and also small notes with the following text:
"In the envelope there is a half of a picture card. The missing part of it has someone who is present here. Try to find him/her. The first 3 pairs get prizes. Good luck!"
It's better to use cards with the pictures of flowers or different post cards in this game. Cut the cards in half in a zigzag line. Then put the halves into envelopes - one half into the white envelope and another into the blue one. You may manage without the envelopes by making a poster with the rules of the game and mounting on the wall.