=RECHERCHEV(STXT(E2;MIN(SI(ESTNUM(STXT(E2;LIGNE(INDIRECT("1:"&NBCAR(E2)));1)*1)*
LIGNE(INDIRECT("1:"&NBCAR(E2)))>0;ESTNUM(STXT(E2;LIGNE(INDIRECT("1:"&NBCAR(E2)));1)*1)*
LIGNE(INDIRECT("1:"&NBCAR(E2)))));MAX(ESTNUM(STXT(E2;LIGNE(INDIRECT("1:"&NBCAR(E2)));1)*1)*
LIGNE(INDIRECT("1:"&NBCAR(E2))))-MIN(SI(ESTNUM(STXT(E2;LIGNE(INDIRECT("1:"&NBCAR(E2)));1)*1)*LIGNE(INDIRECT("1:"&NBCAR(E2)))<>0;ESTNUM(STXT(E2;LIGNE(INDIRECT("1:"&NBCAR(E2)));1)*1)*LIGNE(INDIRECT("1:"&NBCAR(E2)))))+1)*
1;$A$2:$B$28;2;0)