PokerStars No-Limit Hold'em, $1.00 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Hero ($98.70)
BB ($143.35)
UTG ($223.60)
UTG+1 ($23.50)
MP1 ($11.60)
MP2 ($57.05)
MP3 ($50.35)
CO ($98.65)
Button ($34.80)

Preflop: Hero is SB with K, A.
UTG raises to $4, UTG+1 calls $4, 3 folds, CO calls $4, 1 fold, Hero raises to ...

Monkey logic: I'm not folding, calling sucks OOP vs 3 fuckers, must raise, but how much?