C :

#include<stdio.h>
#include<math.h>
int n,m;
double f(double x)
{
	if(x==0)return 0;
	return (n-1)*(x-0.5)/(m-1)+0.5;
}
int equal(double a,double b)
{
	return (a<b+0.000000001)&&(a>b-0.000000001);
}
int main()
{
	int t,ans;
	int i;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%d%d",&n,&m);
		if(m==1){printf("%d\n",n);continue;}
		ans=0;
		for(i=1;i<m;i++)
		{
			if(equal(f(i),(int)f(i)))ans+=(int)f(i)-(int)f(i-1);
			else ans+=(int)f(i)-(int)f(i-1)+1;
		}
		ans+=(int)f(m-0.5)-(int)f(m-1)+1;
		printf("%d\n",ans);
	}
	return 0;
}

C++ :

#include <stdio.h>

int gcd(int x,int y)
{
    return y==0?x:gcd(y,x%y);
}

int main()
{
    //freopen("b.in","r",stdin);
    //freopen("b.out","w",stdout);
    int i,j,n,m,g,T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d%d",&n,&m);
        n--;m--;g=gcd(n,m);
        printf("%d\n",n+m-(n/g%2==m/g%2?g:0)+1);
    }
    return 0;
}