fun f0() { return 0; }
print f0(); // expect: 0
fun f1(a) { return a; }
print f1(1); // expect: 1
fun f2(a, b) { return a + b; }
print f2(1, 2); // expect: 3
fun f3(a, b, c) { return a + b + c; }
print f3(1, 2, 3); // expect: 6
fun f4(a, b, c, d) { return a + b + c + d; }
print f4(1, 2, 3, 4); // expect: 10
fun f5(a, b, c, d, e) { return a + b + c + d + e; }
print f5(1, 2, 3, 4, 5); // expect: 15
fun f6(a, b, c, d, e, f) { return a + b + c + d + e + f; }
print f6(1, 2, 3, 4, 5, 6); // expect: 21
fun f7(a, b, c, d, e, f, g) { return a + b + c + d + e + f + g; }
print f7(1, 2, 3, 4, 5, 6, 7); // expect: 28
fun f8(a, b, c, d, e, f, g, h) { return a + b + c + d + e + f + g + h; }
print f8(1, 2, 3, 4, 5, 6, 7, 8); // expect: 36