Herr Deng桑的教學blog

輸入某一長度字串，如 "how are u" 輸出為： how are u ow are u w are u are u are u re u e u u u

sum=1/1^2+1/2^2+1/3^2+1/4^2+.........+1/n^2+...... 並計算 sqrt(6*sum)