find the fourth
for ( int l = k + 1 ; l < n ; l ++ ) { if ( A [ i ] + A [ j ] + A [ k ] + A [ l ] == X ) System . out . print ( A [ i ] + " ▁ " + A [ j ] + " ▁ " + A [ k ] + " ▁ " + A [ l ] ) ; } } } } }