import std.stdio, std.conv, std.functional, std.string;
import std.algorithm, std.array, std.container, std.range, std.typecons;
import std.bigint, std.numeric, std.math, std.random;
import core.bitop;

string FMT_F = "%.10f";

static File _f;
void file_io(string fn) { _f = File(fn, "r"); }
static string[] s_rd;
T _RD(T = long)() { while(!s_rd.length) s_rd = readln.chomp.split; string res = s_rd[0]; s_rd.popFront; return res.to!T; }
T _RD(T = long)(File f) { while(!s_rd.length) s_rd = f.readln.chomp.split; string res = s_rd[0]; s_rd.popFront; return res.to!T; }
T[] _RDA(T = long)(T fix = 0) { auto r = readln.chomp.split.to!(T[]); r[] += fix; return r; }
T[] _RDA(T = long)(File f, T fix = 0) { auto r = f.readln.chomp.split.to!(T[]); r[] += fix; return r; }
T RD(T = long)() { if (_f.isOpen) return _RD!T(_f); else return _RD!T; }
T[] RDA(T = long)(T fix = 0) { if (_f.isOpen)  return _RDA!T(_f, fix); else return _RDA!T(fix); }

size_t[] MAKE_IDX(alias less = "a < b", Range)(Range range) { auto idx = new size_t[](range.length); makeIndex!(less)(range, idx); return idx;}
size_t MIN_POS(alias less = "a < b", Range)(Range range) { auto r = minPos!(less)(range); return range.length - r.length; }

void chmin(T)(ref T x, T y) { x = min(x, y); } void chmax(T)(ref T x, T y) { x = max(x, y); }
bool inside(T)(T x, T b, T e) { return x >= b && x < e; }
T lcm(T)(T x, T y) { return x * (y / gcd(x, y)); }
double[] rotate(double[] vec, double rad) { return [cos(rad)*vec[0] - sin(rad)*vec[1], sin(rad)*vec[0] + cos(rad)*vec[1]]; }

long mod = 10^^9 + 7;
//long mod = 998_244_353;
//long mod = 1_000_003;
void moda(ref long x, long y) { x = (x + y) % mod; }
void mods(ref long x, long y) { x = ((x + mod) - (y % mod)) % mod; }
void modm(ref long x, long y) { x = (x * y) % mod; }
void modpow(ref long x, long y) { if (!y) { x = 1; return; } auto t = x; x.modpow(y>>1); x.modm(x); if (y&1) x.modm(t); }
void modd(ref long x, long y) { y.modpow(mod - 2); x.modm(y); }

void main()
{
	auto p = RD % 10;
	auto q = RD % 10;
	auto r = RD % 10;
	auto K = RD-1;

	auto arr = new long[][][][][](63, 10, 10, 10);
	foreach (i; 0..10)
	{
		foreach (j; 0..10)
		{
			foreach (k; 0..10)
			{
				auto ni = (i+j+k) % 10;
				auto nj = (j+k+ni) % 10;
				auto nk = (k+ni+nj) % 10;
				arr[0][i][j][k] = [ni, nj, nk];
			}
		}
	}

	foreach (ii; 0..62)
	{
		foreach (i; 0..10)
		{
			foreach (j; 0..10)
			{
				foreach (k; 0..10)
				{
					auto e = arr[ii][i][j][k];
					arr[ii+1][i][j][k] = arr[ii][e[0]][e[1]][e[2]].dup;
				}
			}
		}
	}

	long[] x = [p, q, r];
	auto K3 = K / 3;
	foreach (i; 0..63)
	{
		auto bit = 1L << i;
		if (K3 & bit)
		{
			x = arr[i][x[0]][x[1]][x[2]];
		}
	}

	writeln(x[K%3]);
	stdout.flush;
	debug readln;
}