p005.c

N_NIMCALL(NI64, gcd_92056)(NI64 ia, NI64 ib) {
	NI64 result;
	NI64 a;
	NI64 b;
	nimfr("gcd", "p005.nim")
{	result = 0;
	nimln(3, "p005.nim");
	a = ia;
	nimln(4, "p005.nim");
	b = ib;
	{
		nimln(5, "p005.nim");
		while (1) {
			NI64 tmp;
			NI64 TMP140;
			if (!(IL64(0) < b)) goto LA2;
			nimln(6, "p005.nim");
			tmp = b;
			nimln(7, "p005.nim");
			TMP140 = modInt64(a, b);
			b = (NI64)(TMP140);
			nimln(8, "p005.nim");
			a = tmp;
		} LA2: ;
	}
	nimln(9, "p005.nim");
	result = a;
	goto BeforeRet;
	}BeforeRet: ;
	popFrame();
	return result;
}

N_NIMCALL(NI64, lcm_92047)(NI64 a_92051, NI64 b_92053) {
	NI64 result;
	NI64 TMP139;
	NI64 LOC1;
	NI64 TMP141;
	nimfr("lcm", "p005.nim")
{	result = 0;
	nimln(12, "p005.nim");
	TMP139 = mulInt64(a_92051, b_92053);
	LOC1 = 0;
	LOC1 = gcd_92056(a_92051, b_92053);
	TMP141 = divInt64((NI64)(TMP139), LOC1);
	result = (NI64)(TMP141);
	goto BeforeRet;
	}BeforeRet: ;
	popFrame();
	return result;
}

p005.nim

proc gcd[T](ia,ib: T): T =
    var
        a = ia
        b = ib
    while b > 0:
        a = a mod b
        swap(a, b)
    return a

proc lcm[T](a, b: T): T =
    return (a * b) div gcd(a, b)

var res:int64 = 1
for i in 1..20:
    res = lcm(res, i)
echo res