ggT(1342,65)=20 x 65 + 42
ggT(0065,42)= 01 x 42 + 23
ggT(0042,23)= 01 x 23 + 19
ggT(0023,19)= 01 x 19 + 04
ggT(0019,04)= 04 x 04 + 03
ggT(0004,03)= 01 x 03 + 01
ggT(0003,01)= 03 x 01 + 00
ggT(0001,00)= 1

1342 = 20 x 65 + 42
0065 = 01 x 42 + 23
0042 = 01 x 23 + 19
0023 = 01 x 19 + 04
0019 = 04 x 04 + 03
0004 = 01 x 03 + 01
0003 = 03 x 01 + 00
0001 = 1

1= 4-1x3=4-1x(19-4x4)=5x4 - 19
1=5x(23-1x19)-1x19=5x23-6x19
1=5x23-6x(42-1x23)=11x23-6x42
1=11x(65-1x42)-6x42=11x65-17x42
1=11x65-17x(1342-20x65)=
-17x1342+351x65