View Compilation Error

0_0_18332602_31677.cpp:3:1: error: expected unqualified-id before 'while'
 while(scanf("%lf %lf %lf %lf",&a,&b,&c,&d)!=EOF) {
 ^
0_0_18332602_31677.cpp:4:57: error: expected declaration before '}' token
 s=sqrt((a-c)*(a-c)+(b-d)*(b-d)); printf("%.2lf\n",s); } }
                                                         ^