/* this algorithm takes both arrays and looks for the kth element.
pre-condition: S and T are arrays with the same size and contain integers.
post-condition: the kth element is returned. */
Algorithm input(int S[], int indexS, int T[], int indexT, int k)
if (k = 2)
result <- pick the second smallest element between S[indexS], S[indexS + 1], T[indexT] and T[indexT + 1]
return result;
end IF
int medianOfS <- S[indexS + floor(k/2)];
int medianOfT <- T[indexT + floor(k/2)];
if (medianOfS < medianOfT)
    return input(S, indexS + floor(k/2), T, indexT, ceil(k/2));
end IF
else return input(S, indexS, T, indexT + floor(k/2), ceil(k/2));
end ELSE
END