Let (x) represent the largest integer not greater than x, then, how many groups of natural numbers x and y satisfy (1.9x)+(8.8y)=36?
以(x)表示不大于x的最大整数，那么，满足(1.9x)+(8.8y)=36的自然数x，y的值共有多少组．
<result>4</result>