#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define FF(i, a, b) for(int i=a; i=b; i--) #define REP(i, n) for(int i=0; i eps) return; else if(tmp < -eps) { reverse(ch, ch+len); return; } } } //点p到直线ab的距离 double DistanceToSegment(Point p, Point a, Point b) { if(a == b) return Length(p-a); Vector v1 = b-a, v2 = p-a, v3 = p-b; if(dcmp(Dot(v1, v2)) < 0) return Length(v2); else if(dcmp(Dot(v1, v3)) > 0) return Length(v3); else return fabs(Cross(v1, v2)) / Length(v1); } double dis_pair_seg(Point p1, Point p2, Point p3, Point p4) { return min(min(DistanceToSegment(p1, p3, p4), DistanceToSegment(p2, p3, p4)), min(DistanceToSegment(p3, p1, p2), DistanceToSegment(p4, p1, p2))); } double RC_Distance(Point *ch1, Point *ch2, int n, int m) { int q=0, p=0; REP(i, n) if(ch1[i].y-ch1[p].y < -eps) p=i; REP(i, m) if(ch2[i].y-ch2[q].y > eps) q=i; ch1[n]=ch1[0]; ch2[m]=ch2[0]; double tmp, ans=1e100; REP(i, n) { while((tmp = Cross(ch1[p+1]-ch1[p], ch2[q+1]-ch1[p]) - Cross(ch1[p+1]-ch1[p], ch2[q]- ch1[p])) > eps) q=(q+1)%m; if(tmp < -eps) ans = min(ans,DistanceToSegment(ch2[q],ch1[p],ch1[p+1])); else ans = min(ans,dis_pair_seg(ch1[p],ch1[p+1],ch2[q],ch2[q+1])); p=(p+1)%n; } return ans; } int n, m; Point ch1[10001], ch2[10001]; int main() { while(scanf("%d%d", &n, &m), n+m) { REP(i, n) scanf("%lf%lf", &ch1[i].x, &ch1[i].y); REP(i, m) scanf("%lf%lf", &ch2[i].x, &ch2[i].y); printf("%.5f\n", min(RC_Distance(ch1, ch2, n, m), RC_Distance(ch2, ch1, m, n))); } return 0; }