Problem 5Project Euter

2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.

What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?

#include<iostream>
//#include<cstring>
#include<algorithm>
using namespace std;

_int64 maxCommonDivisor(_int64 a,_int64 b)
{
    _int64 temp;
    if(a<b) swap(a,b);
    while(a%b!=0)
    {
        temp=b;
        b=a%b;
        a=temp;
    }
    return b;
}
int main()
{
    _int64 val;
    val=1;
    for(int i=2;i<=20;++i)
    {
        val=val*i/maxCommonDivisor(val,i);
    }
    printf("%I64d",val);
    return 0;
}