@file:Suppress("DuplicatedCode", "UNUSED_VARIABLE", "SpellCheckingInspection")

import java.io.IOException
import java.io.InputStream
import java.io.PrintWriter
import java.util.NoSuchElementException
import kotlin.math.max

fun main() {
    PrintWriter(System.out).use { out ->
        A.solve(A.FastScanner(), out)
        out.flush()
    }
}

private fun A.solve(sc: A.FastScanner, out: PrintWriter) {
    val (n, m, q) = sc.readIntArray(3)
    val abcd = Array(q) {
        IntArray(4).also {
            it[0] = sc.nextInt() - 1
            it[1] = sc.nextInt() - 1
            it[2] = sc.nextInt()
            it[3] = sc.nextInt()
        }
    }

    fun calc(arr: IntArray): Int {
        return abcd.fold(0) { acc, (a, b, c, d) ->
            if (arr[b] - arr[a] == c) acc + d else acc
        }
    }

    fun loop(pos: Int, min: Int, lst: IntArray): Int {
        var min = min
        if (pos == n) {
            return calc(lst)
        }

        lst[pos] = min

        return if (min == m) loop(pos + 1, min, lst)
        else {
            val a = loop(pos + 1, min, lst)
            lst[pos] = ++min
            val b = if (min == m) {
                for (i in (pos + 1) until n) {
                    lst[pos] = min
                }
                calc(lst)
            } else loop(pos, min, lst)
            max(a, b)
        }
    }

    println(loop(0, 1, IntArray(n) { 1 }))
}

@Suppress("MemberVisibilityCanBePrivate")
private object A {
    class FastScanner {
        private val `in`: InputStream = System.`in`
        private val buffer = ByteArray(1024)
        private var ptr = 0
        private var buflen = 0
        private fun hasNextByte(): Boolean {
            if (ptr < buflen) {
                return true
            } else {
                ptr = 0
                try {
                    buflen = `in`.read(buffer)
                } catch (e: IOException) {
                    e.printStackTrace()
                }
                if (buflen <= 0) {
                    return false
                }
            }
            return true
        }

        private fun readByte(): Int {
            return if (hasNextByte()) buffer[ptr++].toInt() else -1
        }

        operator fun hasNext(): Boolean {
            while (hasNextByte() && !isPrintableChar(buffer[ptr].toInt())) ptr++
            return hasNextByte()
        }

        operator fun next(): String {
            if (!hasNext()) throw NoSuchElementException()

            return buildString {
                var b = readByte()

                while (isPrintableChar(b)) {
                    appendCodePoint(b)
                    b = readByte()
                }
            }
        }

        fun nextLong(): Long {
            if (!hasNext()) throw NoSuchElementException()
            var n: Long = 0
            var minus = false
            var b = readByte()

            if (b == '-'.toInt()) {
                minus = true
                b = readByte()
            }

            if (b < '0'.toInt() || '9'.toInt() < b) {
                throw NumberFormatException()
            }

            while (true) {
                if ('0'.toInt() <= b && b <= '9'.toInt()) {
                    n *= 10
                    n += b - '0'.toInt().toLong()
                } else if (b == -1 || !isPrintableChar(b)) {
                    return if (minus) -n else n
                } else {
                    throw NumberFormatException()
                }

                b = readByte()
            }
        }

        fun nextInt(): Int {
            val nl = nextLong()
            if (nl < Int.MIN_VALUE || nl > Int.MAX_VALUE) throw NumberFormatException()
            return nl.toInt()
        }

        fun nextDouble(): Double {
            return next().toDouble()
        }

        fun readIntArray(n: Int): IntArray {
            val arr = IntArray(n)

            for (i in 0 until n) {
                arr[i] = nextInt()
            }

            return arr
        }

        fun readIntArrayWithMinus1(n: Int): IntArray {
            val arr = IntArray(n)

            for (i in 0 until n) {
                arr[i] = nextInt() - 1
            }

            return arr
        }

        companion object {
            private fun isPrintableChar(c: Int): Boolean {
                return c in 33..126
            }
        }
    }
}


Measured memory_bytes: 36212