题解 | #Number Steps#

#include <stdio.h>
int f1(int x,int y)
{
    if(x%2==0)
    return x*2-2;
    return x*2-3;
}
int f2(int x,int y)
{
    if(x%2==0)
    return x+y;
    return x+y-1;
}
int main()
{
    int x,y;
    while(scanf("%d %d",&x,&y)!=EOF)
    {
        if(x-y==2)
            printf("%d\n",f1(x,y));
        else if(x==y)
            printf("%d\n",f2(x,y));
        else
            printf("No Number\n");
    }  
    return 0;
}