#include <stdio.h>
#include <math.h>
int main(){
    int a,b,c;
    printf("Choisir 2 entiers :\n");
    scanf("%d",&a);
    scanf("%d",&b);
    a = abs(a);
    b = abs(b);
    while (a*b!=0) {
        c=b%a;
        b=a;
        a=c;
    }
    printf("PGCD=%d\n",b);
    return 0;
}