#include <iostream>
#include <cstdint>
 
std::intmax_t F(const std::intmax_t& M, const std::intmax_t& N) {
 
	if (M == 0) { return N + 1; }
	if (N == 0) { return F(M - 1, 1); }
	return F(M - 1, F(M, N - 1));
}
 
int main() {
	std::intmax_t M = 0;
	std::intmax_t N = 0;
	std::intmax_t A = 0;
 
	M = 2;
	N = 1;
	A = F(M, N);
	std::cout << "F(" << M << ',' << N << ")=" << A << std::endl;
 
	M = 4;
	N = 1;
	A = F(M, N);
	std::cout << "F(" << M << ',' << N << ")=" << A << std::endl;
 
	return 0;
}

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