Conversion of Millions to Billions using R without splitting the column? [closed]

$1.2 B $2.3 B $3 B   $3.5 B $1.3 B $808 M $3.8 B $3.8 B $135 M $2.8 B $3.3 B $3.3 B $4.6 B
$196 M $79 M  $3 B   $1.8 B $2.4 B $2.5 B $3.3 B $2.7 B $9.2 B $439 M $2.3 B $900 M $2.8 B
$784 M $2.3 B $884 M $4.3 B $88 M  $653 M $2.9 B $9.2 B $1.3 B $269 M $199 M $862 M $2.6 B
$1.1 B $652 M $1.8 B $5.2 B $130 M $1.9 B $834 M $174 M $2.6 B $1.8 B $724 M $218 M $2.6 B
$3.2 B $407 M $1.8 B $256 M $1.6 B $570 M $992 M $3.5 B $1 B   $2.8 B

Above are the column values of data frame need help with conversion of Millions to Billions