c语言的题，计算并求出1-3+5-7+。。。-99+101的值

#include <stdio.h>
int main(void){
long int sum,sum1,z;
for(int i = 1,j = -3;i < 102;i += 4){
sum += i;
j += 4;
sum1 += j;
}
z =sum - sum1;
printf("%i",z);
return 0;
}