大神们帮我看看哪错了？为什么数一大就不对了。。。

#include "stdio.h"
#include "math.h"
long long jdz(long long x)
{
if (x < 0)
x = -x;
return (x);
}
int rn(int x)
{
int k;
if (x % 400 == 0 || x % 100!= 0 && x % 4 == 0)
k = 28;
else
k = 29;
return (k);
}
long long ts(int y, int m, int d)
{
long long a[13], i, j;
long long z;
z = 0;
for (i = 1; i <= 7; i=i+2)
a[i] = 31;
for (i = 8; i <= 12; i = i + 2)
a[i] = 31;
a[4] = a[6] = a[9] = a[11] = 30;
for (i = 1; i <= y-1; i++)
{
a[2] = rn(i);
for (j = 1; j <= 12;j++)
z = z + a[j];
}
a[2] = rn(y);
for (i = 1; i <= m - 1; i++)
z = z + a[i];
z = z + d;
return (z);
}
int main()
{
long long a, b,j,h;
long long c;
int y, m, d,e;
scanf_s("%d,%d,%d", &y, &m, &d);
a = ts(2013, 12, 9);
b = ts(y, m, d);
c = a - b;
j = jdz(c);
e = (c*(j % 7)) / j;
switch (e)
{
case 1:case -6: printf("星期二"); break;
case 2:case -5: printf("星期三"); break;
case 3:case -4: printf("星期四"); break;
case 4:case -3: printf("星期五"); break;
case 5:case -2: printf("星期六"); break;
case 6:case -1: printf("星期日"); break;
case 0: printf("星期一"); break;
default:break;
}
}