#include<iostream>
using namespace std;

int main(){
	int a,b,c;
	int i=1;
	int e=0;
	  1<=a&&a<=10000;
	  1<=b&&b<=10000;
	  1<=c&&c<=10000;
	  a<=b;
	  cin>>a>>" ">>b>>" ">>c;
	for(d=a;d<=b;d++){
		if(c%d=0){
			e+=i;
			i+=1;
		}
	}
	cout<<e<<endl;
	return 0;
}