Find the required periodic string with period 2
else { char [ ] arr = new char [ l ] ; for ( int i = 0 ; i < l ; i += 2 ) { arr [ i ] = '1' ; arr [ i + 1 ] = '0' ; } for ( int i = 0 ; i < l ; i ++ ) Console . Write ( arr [ i ] ) ; Console . WriteLine ( ) ; } }