#Z1
function Z1()
{
    Licznik=$(echo "($1-$2)" | bc)
    Mianownik=$(echo "($1+$2)" | bc)
    if [[ $Mianownik -eq 0 ]]; then
        echo "Mianownik = 0"
        exit -1
    fi

    Z1=$(echo "scale=5; $Licznik/$Mianownik" | bc)
    echo $Z1
}

#Z2
function Z2()
{
    if [[ $# -ne 1 ]]; then
        echo "Podano =/= 1 argument"
        exit -1
    fi

    if [ $1 -le 0 ]; then
        echo 0

    elif [ $1 -eq 0 ]; then
        echo 0

    elif [ $1 -le 2 ]; then
        echo 1

    else
        x1=$(Z2 $[$1-1])
        x2=$(Z2 $[$1-2])
        echo $(($x1+$x2))
    fi
 }

#Z3
function Z3()
{
    if [[ $# -ne 1 ]]; then
        echo "Podano =/= 1 argument"
        exit -1
    fi

    if [ $1 -le 0 ]; then
        echo 0

    elif [ $1 -eq 0 ]; then
        echo 0

    elif [ $1 -le 2 ]; then
        echo 1

    else
    x0=0;
    x1=1;

    for((i=1;i<$1;++i)); do
        temp=$(($x0+$x1))
        x0=$x1
        x1=$temp
    done
    fi
    echo $x1
}

function Z4()
{

}

Z1 $1 $2
Z2 $3
Z3 $4