=SI(MOD(COLONNE();2)=1;GRANDE.VALEUR(SI(MOD(COLONNE($C$12:$J$12);2)=0;$C$12:$J$12+COLONNE($C$12:$J$12)/10^9);(COLONNE()-5)/2);INDEX($C$12:$J$12;;EQUIV(GRANDE.VALEUR(SI(MOD(COLONNE($C$12:$J$12);2)=0;$C$12:$J$12+(COLONNE($C$12:$J$12)/10^9));(COLONNE()-4)/2);$C$12:$J$12+(COLONNE($C$12:$J$12)/10^9);0)-1))