h2 h3 h4 Block Block FC FC FC FC Block Self-attention 3 .4 18𝒉 𝟒 𝒉 𝟑 𝒉 𝒉 𝟏 𝟐 𝒙 𝟒 𝒙 𝟑 𝒙 𝟐 𝒙 𝟏 Block Block Block … … … … FC FC FC FC Self-attention 18