#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
void*wmem;
char memarr[96000000];
template<class T> inline void walloc1d(T **arr, int x, void **mem = &wmem){
  static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
  (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] );
  (*arr)=(T*)(*mem);
  (*mem)=((*arr)+x);
}
template<class T> inline void walloc1d(T **arr, int x1, int x2, void **mem = &wmem){
  walloc1d(arr, x2-x1, mem);
  (*arr) -= x1;
}
template<class T1> void sortV_L(vector<T1> &a, void *mem = wmem){
  sort(a.begin(), a.end());
}
template<class T1> void rsortV_L(vector<T1> &a, void *mem = wmem){
  sortV_L(a, mem);
  reverse(a.begin(), a.end());
}
inline int my_getchar(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar(a);
}
inline void wt_L(int x){
  int s=0;
  int m=0;
  char f[10];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar('-');
  }
  while(s--){
    my_putchar(f[s]+'0');
  }
}
inline void wt_L(unsigned x){
  int s=0;
  char f[10];
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  while(s--){
    my_putchar(f[s]+'0');
  }
}
inline void wt_L(long long x){
  int s=0;
  int m=0;
  char f[20];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar('-');
  }
  while(s--){
    my_putchar(f[s]+'0');
  }
}
inline void wt_L(unsigned long long x){
  int s=0;
  char f[21];
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  while(s--){
    my_putchar(f[s]+'0');
  }
}
int WRITER_DOUBLE_DIGIT = 15;
inline int writerDigit_double(){
  return WRITER_DOUBLE_DIGIT;
}
inline void writerDigit_double(int d){
  WRITER_DOUBLE_DIGIT = d;
}
inline void wt_L(double x){
  const int d = WRITER_DOUBLE_DIGIT;
  int k;
  int r;
  double v;
  if(x!=x || (x==x+1 && x==2*x)){
    my_putchar('E');
    my_putchar('r');
    my_putchar('r');
    return;
  }
  if(x < 0){
    my_putchar('-');
    x = -x;
  }
  x += 0.5 * pow(0.1, d);
  r = 0;
  v = 1;
  while(x >= 10*v){
    v *= 10;
    r++;
  }
  while(r >= 0){
    r--;
    k = floor(x / v);
    if(k >= 10){
      k = 9;
    }
    if(k <= -1){
      k = 0;
    }
    x -= k * v;
    v *= 0.1;
    my_putchar(k + '0');
  }
  if(d > 0){
    my_putchar('.');
    v = 1;
    for(r=(0);r<(d);r++){
      v *= 0.1;
      k = floor(x / v);
      if(k >= 10){
        k = 9;
      }
      if(k <= -1){
        k = 0;
      }
      x -= k * v;
      my_putchar(k + '0');
    }
  }
}
inline void wt_L(const char c[]){
  int i=0;
  for(i=0;c[i]!='\0';i++){
    my_putchar(c[i]);
  }
}
inline void wt_L(string &x){
  int i=0;
  for(i=0;x[i]!='\0';i++){
    my_putchar(x[i]);
  }
}
template<class T> int LIS_length(int n, T a[], void *mem = wmem){
  int i;
  int k;
  int res;
  T*arr;
  if(n==0){
    return 0;
  }
  walloc1d(&arr, n, &mem);
  arr[0] = a[0];
  res = 1;
  int YOSCSEHU = n;
  for(i=(1);i<(YOSCSEHU);i++){
    k = lower_bound(arr, arr+res, a[i]) - arr;
    arr[k] = a[i];
    if(res==k){
      res++;
    }
  }
  return res;
}
vector<int> cor[1000+10];
int N;
int M;
int Q;
int A[1000000+10];
int B[1000000+10];
int C[1000000+10];
int csz;
int main(){
  int i;
  wmem = memarr;
  csz = 0;
  rd(N);
  rd(M);
  rd(Q);
  {
    int PiIOrLma;
    for(PiIOrLma=(0);PiIOrLma<(Q);PiIOrLma++){
      rd(A[PiIOrLma]);A[PiIOrLma] += (-1);
      rd(B[PiIOrLma]);B[PiIOrLma] += (-1);
    }
  }
  for(i=(0);i<(Q);i++){
    cor[A[i]].push_back(B[i]);
  }
  for(i=(0);i<(N);i++){
    rsortV_L(cor[i]);
  }
  for(i=(0);i<(N);i++){
    int j;
    for(j=(0);j<(cor[i].size());j++){
      C[csz++] = cor[i][j];
    }
  }
  wt_L(LIS_length(csz, C));
  wt_L('\n');
  return 0;
}
// cLay version 20210405-1

// --- original code ---
// //no-unlocked
// VI cor[1d3+10];
// int N, M, Q;
// int A[1d6+10], B[1d6+10];
// int C[1d6+10], csz;
// {
//     csz = 0;
//     rd(N, M, Q, (A--,B--)(Q));
//     rep(i, Q){
//         cor[A[i]].push_back(B[i]);
//     }
//     rep(i, N) rsortV(cor[i]);
//     rep(i, N){
//         rep(j, cor[i].size()){
//             C[csz++] = cor[i][j];
//         }
//     }
//     wt(LIS_length(csz, C));
// }