my loop is looping one less time

[Toshinari]

I wrote a code to find the lcm of multiple numbers, but the loop is looping one less time. The first line of the input contains a positive integer N, and each of the next N lines contains 2 space-separated integers. The code will then add each of the two intengers and calculate the lcm of the sums. I think I have made a stupid mistake in the last loop, but I can't find it. I am a beginner, so please point out my stupid mistake in the code. Thank you!

#include <cstdio>
lcm (int x, int y){
	if (x > y){
	        for (int i = 1; i <= y; i++){
			if ((x * i) % y == 0){
				int lcm = x * i;
				return lcm;
				break;
			}
		}
	}else if (x < y){
		for (int i = 1; i <= x; i++){
			if ((y * i) % x == 0){
				int lcm = y * i;
				return lcm;
				break;
			}
		}
	}
}
int main (){
	int number = 0;
	scanf("%d",&number);
	int a[number] = { };//The first intengers or the sum of the 2 intengers
	int b[number] = { };//The second intengers
	int c = 1;
	while (c < number){
		scanf("%d %d\n",&a[c],&b[c]);
		a[c] += b[c];
		c++;
	}
	int n = 1;
	int d = 0;
	while (d < number){
		n = lcm(n, a[d]);
		if (d == number - 1){
			printf("%d\n",n);	
		}
		d++;
	}	
}

Some inputs and outputs:
test1:
3 input
1 3 input
2 4 input
5 8 input
12 output

test2:
4 input
1 2 input
2 3 input
3 4 input
4 5 input
105 output

[ne555]

	int c = 1;
	while (c < number){

suppose that you just have one testcase. So number is 1.
1<1 is false.

[Toshinari]

thank you!
but now the second last loop is running one more time and force me to input number + 1 times.

[ne555]

let me see if I understand.
The second loop was working fine, but you decided to edit it. Now it fails, but you don't think that it's necessary to show your changes.

good luck