#include <cstdio>

using namespace std;

int a,b,mij,st,dr;

int main()
{
    FILE *f=fopen("suma.in","r");
    FILE *g=fopen("suma.out","w");
    fscanf(f,"%d %d",&a,&b);
    dr=0x7fffffff;
    st=1;
    mij=0x7fffffff/2;
    while(mij-a!=b)
    {
        if(mij-a>b)dr=mij-1;
        else
        if(mij-a<b)st=mij+1;
        mij=(st+dr)/2;
    }
    fprintf(g,"%d",mij);
    fclose(f);
    fclose(g);
    return 0;
}