C :

#include<stdio.h>
int main(){
	int a, b, c, d;
	double ping;
	scanf("%d%d%d%d", &a, &b, &c, &d);
	ping = (a + b + c + d) / 4.0;
	printf("%.2lf", ping);
	return 0;
}

C++ :

#include<stdio.h>
int main(){
	int a,b,c,d;
	float ave;
	scanf("%d %d %d %d",&a,&b,&c,&d);
	ave=(a+b+c+d)/4.0;
	printf("%1.2f\n",ave);
	return 0;
}

Pascal :

var a,b,c,d:real;
begin
  readln(a,b,c,d);
  writeln((a+b+c+d)/4:0:2);
end.