#include <iostream>
#include <string>
using namespace std;
int main()
{
int h,w,n,page=1;
int count = 0;
int a = 0;
cin>>h>>w>>n;
string str;
for(int i = 1;i <=n;i++)
{
cin>>str;
count+= str.length()+a;
if(count> w)
{
count = str.length();
a = 1;
page++;
}
else if(count ==w)
{
    count = 0;
    a =0;
if(i<n)
    page++;
}
else
{
a++;
}
}
if(page%h==0)
cout<<page/h;
else
cout<<((page/h)+1);
return 0;
}