'''Pell's equation''' (also called the '''Pell–Fermat''' equation) is a [https://en.wikipedia.org/wiki/Diophantine_equation Diophantine equation] of the form:
:::::: x2 - ny2 = 1
with integer solutions for '''x''' and '''y''', where '''n''' is a given non-square positive integer.
;Task requirements:
:* find the smallest solution in positive integers to Pell's equation for '''n''' = {61, 109, 181, 277}.
;See also:
:* Wikipedia entry: [https://en.wikipedia.org/wiki/Pell%27s_equation Pell's equation].