class Queue {
    private sIn: number[] = []
    private sOut: number[] = []
    private top: number
    
    add(e: number) {
        if (this.sIn.length === 0) this.top = e
        this.sIn.push(e)
    }
    
    pop(): number {
        if (this.sOut.length === 0) {
            while(this.sIn.length > 0) {
                this.sOut.push(this.sIn.pop())
            }
        }
        return this.sOut.pop()
    }
    
    peek():number {
        return this.sOut[this.sOut.length - 1] ?? this.top
    }
}

function handler() {
    const q = new Queue()
    for (let i = 1; i < inputLines.length; i++) {
        const [c, p] = inputLines[i].split(' ')
        if (c === '1') q.add(parseInt(p))
        else if (c === '2') q.pop()
        else console.log(q.peek())
    }
}