题解 | #Number Steps#

#include <iostream>
#include <string>

using namespace std;


int getting(int x, int y){
    int value = -1;
    int m = x/2;
    if(x%2 == 0){ 
        if(x == y){
            value = 4*m;
        }
        else if(x -y == 2){
            value = 4*m -2;
        }
    }
    else if(x%2 == 1){
        if(x == y){
            value = 4*m +1;
        }
        else if(x == y+2){
            value = 4*m -1;
        }
    }
    return value;
}

int main(){
    int x , y;
    while( cin >> x >> y){
        int value = getting(x, y);
        if(value == -1){
            cout << "No Number" << endl;
        }
        else{
            cout << value << endl;
        }
    }
}