#include<cstdio>

#include<algorithm>

#include<cstring>

#include<stack>

using namespace std;

char s[301],p[301];

int q[301];

int len,j,ret = 0;

int main()

{

while(1)

{

s[++len] = getchar();

if(s[len] == '@') break;

if(s[len] >= '0' && s[len] <= '9') ret = ret * 10 + (s[len] - '0');

if(s[len] == ' ' && s[len - 1] >= '0' && s[len - 1] <= '9')

{

q[++j] = ret;

ret = 0;

}

if(s[len] == '+') q[--j] = q[j] + q[j + 1];

if(s[len] == '-') q[--j] = q[j] - q[j + 1];

if(s[len] == '*') q[--j] = q[j] * q[j + 1];

if(s[len] == '/') q[--j] = q[j] / q[j + 1];

}

printf("%d\n",q[j]);

return 0;

}