To provide a novel shift register. Transistors 101 to 104 are provided. A first terminal of the transistor 101 is connected to a wiring 111 and a second terminal of the transistor 101 is connected to a wiring 112. A first terminal of the transistor 102 is connected to a wiring 113 and a second terminal of the transistor 102 is connected to the wiring 112. A first terminal of the transistor 103 is connected to the wiring 113 and a gate of the transistor 103 is connected to the wiring 111 or a wiring 119. A first terminal of the transistor 104 is connected to a second terminal of the transistor 103, a second terminal of the transistor 104 is connected to a gate of the transistor 101, and a gate of the transistor 104 is connected to a gate of the transistor 102.