如何添加排除负数

Write a program that queries the user for three positive integers and
displays messages:

All numbers are equal if all three numbers are equal

Two numbers are equal if any two numbers out of three are equal

All numbers are different if all three numbers entered are different


If there is an error in the input data, e.g., negative numbers are
entered, the program should display the message Invalid Input

package main

import (
    "fmt"
)

func main() {
    var a, b, c int
    fmt.Scan(&a)
    fmt.Scan(&b)
    fmt.Scan(&c)
    if (a != b && a > 0) && (b != c && c > 0) && (a != c && b > 0) {
        fmt.Print("All the numbers are different")
    } else if a == b && b == a && a == c && c == b {
        fmt.Print("All numbers are equal")
    } else if (a == b && b > 0) || (b == a && a > 0) || (c == a && a > 0) || (c == b && b > 0) {
        fmt.Print("Two numbers are equal")
    } else {
        fmt.Print("Invalid request")
    }
}

package main

import (
    "fmt"
)

func main() {

    var a int = 5
    var b int = 9
    var c int = 5

    fmt.Scan(&a)
    fmt.Scan(&b)
    fmt.Scan(&c)

    s := map[int]bool{a: true, b: true, c: true}

    if a < 0 || b < 0 || c < 0 {
        fmt.Print("Invalid request")
    } else if len(s) == 3 {
        fmt.Print("All the numbers are different")
    } else if len(s) == 2 {
        fmt.Print("Two numbers are equal")
    } else if len(s) == 1 {
        fmt.Print("All numbers are equal")
    }

}