Driver code
public static void main ( String [ ] args ) { pair a [ ] = { new pair ( 1 , 3 ) , new pair ( 4 , 7 ) , new pair ( 8 , 11 ) } ; int n = a . length ; int k = 6 ; int index = findNumber ( a , n , k ) ; if ( index != - 1 ) System . out . println ( index ) ; else System . out . println ( - 1 ) ; } }