#include <iostream>
using namespace std;
int main()
{
unsigned a, b, nrSchimb=0, i, j, sus, jos, dreapta, stanga, colt;
cin>>a>>b;
sus=1; dreapta=1; jos=0; stanga=0;
a++; b++;
i=b; j=1;
colt=0;
while(!colt){
if(sus) i--;
if(dreapta) j++;
if(jos) i++;
if(stanga) j--;
if((i==1 && j==1) || (i==1 && j==a) || (i==b && j==1) || (i==b && j==a))
colt=1;
else{
if(i==1){jos=1; sus=0; nrSchimb++;}
if(i==b){jos=0; sus=1; nrSchimb++;}
if(j==1){dreapta=1; stanga=0; nrSchimb++;}
if(j==a){dreapta=0; stanga=1; nrSchimb++;}
}
}
cout<<nrSchimb;
return 0;
}