import kotlin.math.max

fun main() = abc176e()

@OptIn(ExperimentalStdlibApi::class)
fun abc176e() = IO_abc176e().exec {
    val (h, w, m) = List(3) { readInt() }
    val targets = Array(h) { mutableListOf<Int>() }
    val wCount = LongArray(w)
    repeat(m) {
        val h1 = readInt() - 1
        val w1 = readInt() - 1
        targets[h1].add(w1)
        wCount[w1]++
    }

    val segmentTree = SegmentTree(wCount, 0L, Math::max)

    var answer = 0L

    repeat(h) { i ->
        targets[i].forEach { j -> segmentTree[j]-- }
        answer = max(answer, targets[i].size + segmentTree[0 until w])
        targets[i].forEach { j -> segmentTree[j]++ }
    }

    println(answer)
}

private class SegmentTree(init: LongArray, val identityElement: Long, val monad: (Long, Long) -> Long) {
    val indices: Int
    val nodes: LongArray

    init {
        var indices = 1
        while (indices < init.size) indices = indices shl 1
        val nodes = LongArray(2 * indices - 1) { identityElement }
        for (i in init.indices) nodes[i + indices - 1] = init[i]
        for (i in indices - 2 downTo 0) nodes[i] = monad(nodes[2 * i + 1], nodes[2 * i + 2])
        this.indices = indices
        this.nodes = nodes
    }

    operator fun set(x: Int, value: Long) {
        var index = x + indices - 1
        nodes[index] = value
        while (index > 0) {
            index = (index - 1) / 2
            nodes[index] = monad(nodes[2 * index + 1], nodes[2 * index + 2])
        }
    }

    operator fun get(range: IntRange) = get(range.first, range.last + 1)
    operator fun get(index: Int) = get(index, index + 1)

    fun get(a: Int, b: Int, k: Int = 0, l: Int = 0, r: Int = indices): Long {
        if (r <= a || b <= l) return identityElement
        if (a <= l && r <= b) return nodes[k]
        return monad(
            get(a, b, 2 * k + 1, l, (l + r) / 2),
            get(a, b, 2 * k + 2, (l + r) / 2, r)
        )
    }
}

// region kokokara template dayo (^o^)
@Suppress("unused", "ClassName", "SpellCheckingInspection", "ConvertToStringTemplate", "MemberVisibilityCanBePrivate")
private class IO_abc176e(private val separator: String = System.lineSeparator()) {
    private val input = System.`in`
    private val buffer = ByteArray(1024)
    private var pointer = 0
    private var bufferLength = 0
    private val sb = StringBuilder()
    private fun Byte.isPrintable() = this in 33..126
    private fun Byte.isNumeric() = this in '0'.toByte()..'9'.toByte()
    private fun Byte.toNumVal() = if (this.isNumeric()) this - '0'.toByte() else error("$this is not numeric")

    private fun hasNextByte(): Boolean {
        return if (pointer < bufferLength) true else {
            pointer = 0
            bufferLength = input.read(buffer)
            bufferLength > 0
        }
    }

    private fun readByte(): Byte = if (hasNextByte()) buffer[pointer++] else -1
    private fun skipUnprintable() = run { while (hasNextByte() && !buffer[pointer].isPrintable()) pointer++ }
    private fun hasNext(): Boolean = run { skipUnprintable() }.run { hasNextByte() }
    private fun hasNextOrError() = if (!hasNext()) error("has no next element.") else Unit

    fun readString(): String {
        hasNextOrError()
        val sb = StringBuilder()
        var b = readByte()
        while (b.isPrintable()) {
            sb.appendCodePoint(b.toInt())
            b = readByte()
        }
        return sb.toString()
    }

    fun readLong(): Long {
        hasNextOrError()
        var n = 0L
        var negative = false
        var b = readByte()
        if (b == '-'.toByte()) {
            negative = true
            b = readByte()
        }
        if (!b.isNumeric()) error("$b is not numeric.")
        while (true) {
            when {
                b.isNumeric() -> n = n * 10 + b.toNumVal()
                b.toInt() == -1 || !b.isPrintable() -> return if (negative) -n else n
                else -> error("failed to parse. [n=$n, b=$b]")
            }
            b = readByte()
        }
    }

    fun readInt() = readLong()
        .let { if (it in Int.MIN_VALUE..Int.MAX_VALUE) it.toInt() else error("$it is not in range of Int.") }

    fun readDouble(): Double {
        var n = 0.0
        var div = 1.0
        var negative = false
        var b = readByte()
        if (b == '-'.toByte()) {
            negative = true
            b = readByte()
        }
        do n = n * 10 + b.toNumVal()
        while (run { b = readByte() }.run { b.isNumeric() })
        if (b == '.'.toByte()) {
            while (run { b = readByte() }.run { b.isNumeric() })
                n += b.toNumVal() / (run { div *= 10 }.run { div })
        }
        return if (negative) -n else n
    }

    fun println(): Unit = run { sb.append(separator) }
    fun print(any: Any): Unit = run { sb.append(any) }
    fun println(any: Any): Unit = run { sb.append(any.toString() + separator) }
    fun flush() = run { kotlin.io.println(sb); sb.clear() }

    fun exec(action: IO_abc176e.() -> Unit) {
        var t: Throwable? = null
        Thread(null, { action() }, "solve", 128 * 1024 * 1024)
            .apply { setUncaughtExceptionHandler { _, t1 -> t = t1 } }
            .apply { start() }.join()
        t?.let { throw it }
        kotlin.io.print(sb)
    }

    fun readLine(): Nothing = error("readLine is disabled.")
}
// endregion kokomade template dayo (^o^)


Measured memory_bytes: 133244