Lauri has between 50 and 100 pennies. When she stacks them in piles of 2, she has one
penny left over. When she stacks them in piles of 3, she has one penny left over. When she
stacks them in piles of 4, she has one penny left over. However, when she stacks them in
piles of 5, there are no pennies left over. How many pennies does Lauri have?