#include <iostream>

int main()
{
	int 
		N, M, C;
	unsigned int 
		value(0);
	std::cin >> N >> M >> C;
	
	for(int i = N; i < (M+1); i++)
	{
		int tmp = i;
		while(tmp)
		{
			if(C == (tmp % 10))
			{
				value++;
				break;
			}
			tmp /= 10;
		}
	}
	std::cout << "Количество = " << value << std::endl;
	return 0;
}