\ifgerman
    \newcommand{\ibrsignature}{Datum, Unterschrift}
\else
    \newcommand{\ibrsignature}{Date, Signature}
\fi

\newcommand{\supervisors}[3]{
	\newcounter{SupervisorsCounter}
	\def\temp{#1}\ifx\temp\empty
		\newcommand{\supervisorone}{}
		\newcommand{\supervisoronesign}{}
	\else
		\newcommand{\supervisorone}{#1\\}
		\newcommand{\supervisoronesign}{
		#1           & \rule[-0.5ex]{\linewidth}{1pt}\newline\itshape(\ibrsignature)\\[5ex]
		}
		\stepcounter{SupervisorsCounter}
	\fi

	\def\temp{#2}\ifx\temp\empty
		\newcommand{\supervisortwo}{}
		\newcommand{\supervisortwosign}{}
	\else
		\newcommand{\supervisortwo}{#2\\}
		\newcommand{\supervisortwosign}{
		#2           & \rule[-0.5ex]{\linewidth}{1pt}\newline\itshape(\ibrsignature)\\[5ex]
		}
		\stepcounter{SupervisorsCounter}
	\fi

	\def\temp{#3}\ifx\temp\empty
		\newcommand{\supervisorthree}{}
		\newcommand{\supervisorthreesign}{}
	\else
		\newcommand{\supervisorthree}{#3\\}
		\newcommand{\supervisorthreesign}{
		#3           & \rule[-0.5ex]{\linewidth}{1pt}\newline\itshape(\ibrsignature)\\[5ex]
		}
		\stepcounter{SupervisorsCounter}
	\fi

	\ifnum\theSupervisorsCounter=1
		\newcommand{\supervisorstring}{Supervisor:}
	\else
		\newcommand{\supervisorstring}{Supervisors:}
	\fi
}