Enchanted Book of Strength

{x}= 1
Assign target creature you control an additional +1/0
{x}= 2
Assign target creature you control an additional +2/0
{x}= 3
Assign target creature you control an additional +3/0
{x}= 4
Assign target creature you control an additional +4/0
{x}= 5
Assign target creature you control an additional +5/0