PPCM Finder (Exercice 13 ISI)

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int a,b,i;
    do{
        printf ("Saisir A: ");
        scanf ("%d",&a);
        printf ("\nSaisir B: ");
        scanf ("%d",&b);
    }while (a<=0 || b<=0 || a<=b);
    i=1;
    do{
        i++;
    }while (i%a!=0 || i%b!=0);
    printf ("Le PPCM est %d",i);
}