#include<stdio.h>int main()
{int i, j;long long sum = 0, jieCheng;for (i = 1; i <= 20; i++){jieCheng = 1;for (j = 1; j <= i; j++){jieCheng *= j;}sum += jieCheng;}printf("%lld", sum);return 0;
}
#include<stdio.h>int main()
{int i, j;long long sum = 0, jieCheng;for (i = 1; i <= 20; i++){jieCheng = 1;for (j = 1; j <= i; j++){jieCheng *= j;}sum += jieCheng;}printf("%lld", sum);return 0;
}