#include<bits/stdc++.h> using namespace std; int n,m,k,a[1005][1005],dp[1005][1005]; double d=141.421356; int main(){ memset(a,0,sizeof(a)); memset(dp,0,sizeof(dp)); cin>>n>>m; cin>>k; for(int i=1;i<=k;i++){ int t1,t2; cin>>t1>>t2; a[t1][t2]=1; dp[t1][t2]=1; } for(int i=1;i<=n;i++){ for(int j=1;j<=m;j++){ if(i>1&&j>1&&dp[i][j]==1) dp[i][j]=max(dp[i][j],dp[i-1][j-1]+1); dp[i][j]=max(dp[i-1][j],max(dp[i][j],dp[i][j-1])); } } d=dp[n][m]*d; double ans=(n+m-dp[n][m]*2)*100+d; cout<<round(ans)<<endl; return 0; }