var
	f: array[1..100000] of longint;
	a, b, n, i: longint;
	p, q, k, j: longint;
	flag: boolean;
	
begin
	assign(input, 'sequenceb.in'); reset(input);
	assign(output, 'sequenceb.out'); rewrite(output);
	read(a, b, n);
	f[1] := 1; f[2] := 1;
	flag := true; i := 3;
	while flag do
	begin
		f[i] := (a * f[i - 1] + b * f[i - 2]) mod 7;
		if i mod 2 = 0 then
		begin
			p := 1; q := i div 2 + 1;
			for j := 1 to i div 2 do
				if f[p] = f[q] then
				begin
					inc(p); inc(q);
				end else break;
			dec(p);
			if p = i div 2 then
			begin
				k := p; flag := false;
			end;
		end;
		inc(i);
	end;
	write(f[(n - 1) mod k + 1]);
	close(input); close(output);
end.