import java.io.*;

class Vec1 {
public void naiseki(double[] a, double[] b, double[] c) {
for(int i = 0; i < a.length; i++)
c[i] += a[i] * b[i];
}
}

public class VecSousa1 {
public static void main(String[] args) {
Vec1 vec = new Vec1();
double[] a = {1, 2, 3};
double[] b = {2, 3, 4};
double[] c = {0, 0, 0};
vec.naiseki(a, b, c);
System.out.print("内積 a・b = {");
for(int i = 0; i < c.length; i++){
System.out.print(c[i] + ((i < c.length - 1) ? ", " : "}\n"));
}
}
}