import java.io.BufferedReader
import java.io.InputStreamReader

fun main() {
    val root = Node()
    val buffer = BufferedReader(InputStreamReader(System.`in`))
    val inputString = buffer.readLine()
    repeat(buffer.readLine().toInt()) {
        root.add(buffer.readLine().reversed())
    }
    val dp = BooleanArray(inputString.length + 1)
    dp[0] = true

    for (i in 1..dp.lastIndex) {
        var curNode = root
        var stringIndex = i - 1
        while (stringIndex >= 0) {
            val curChar = inputString[stringIndex]
            curNode = curNode.followings[curChar] ?: break
            if (curNode.isTerminal && dp[stringIndex]) {
                dp[i] = true
                break
            }
            --stringIndex
        }
    }
    if (dp.last()) println("YES")
    else println("NO")
}

class Node {
    var isTerminal = false
    val followings = mutableMapOf<Char, Node>()
}

fun Node.add(string: String, curPos: Int = 0): Node {
    return if (curPos == string.length) {
        isTerminal = true
        this
    } else {
        val nextChar = string[curPos]
        this.followings.putIfAbsent(nextChar, Node())
        val nextNode = this.followings[nextChar]
        nextNode!!.add(string, curPos + 1)
    }
}