#pragma GCC optimize ("Ofast") #include using namespace std; void *wmem; char memarr[96000000]; inline int my_getchar_unlocked(){ static char buf[1048576]; static int s = 1048576; static int e = 1048576; if(s == e && e == 1048576){ e = fread_unlocked(buf, 1, 1048576, stdin); s = 0; } if(s == e){ return EOF; } return buf[s++]; } inline void rd(int &x){ int k; int m=0; x=0; for(;;){ k = my_getchar_unlocked(); if(k=='-'){ m=1; break; } if('0'<=k&&k<='9'){ x=k-'0'; break; } } for(;;){ k = my_getchar_unlocked(); if(k<'0'||k>'9'){ break; } x=x*10+k-'0'; } if(m){ x=-x; } } inline int rd(char c[]){ int i; int sz = 0; for(;;){ i = my_getchar_unlocked(); if(i!=' '&&i!='\n'&&i!='\r'&&i!='\t'&&i!=EOF){ break; } } c[sz++] = i; for(;;){ i = my_getchar_unlocked(); if(i==' '||i=='\n'||i=='\r'||i=='\t'||i==EOF){ break; } c[sz++] = i; } c[sz]='\0'; return sz; } inline void rd(string &x){ char *buf = (char *)wmem; rd(buf); x = buf; } inline int rd_int(void){ int x; rd(x); return x; } struct MY_WRITER{ char buf[1048576]; int s; int e; MY_WRITER(){ s = 0; e = 1048576; } ~MY_WRITER(){ if(s){ fwrite_unlocked(buf, 1, s, stdout); } } } ; MY_WRITER MY_WRITER_VAR; void my_putchar_unlocked(int a){ if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){ fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout); MY_WRITER_VAR.s = 0; } MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a; } inline void wt_L(char a){ my_putchar_unlocked(a); } inline void wt_L(int x){ int s=0; int m=0; char f[10]; if(x<0){ m=1; x=-x; } while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } if(m){ my_putchar_unlocked('-'); } while(s--){ my_putchar_unlocked(f[s]+'0'); } } string A; int sz; int s[100]; int main(){ int Lj4PdHRW; wmem = memarr; int KL2GvlyY = rd_int(); for(Lj4PdHRW=(0);Lj4PdHRW<(KL2GvlyY);Lj4PdHRW++){ rd(A); if(A=="+"){ sz--; s[sz-1] = s[sz-1] + s[sz]; } else if(A=="-"){ sz--; s[sz-1] = s[sz-1] - s[sz]; } else{ s[sz++] = atoi(A.c_str()); } } wt_L(s[0]); wt_L('\n'); return 0; } // cLay varsion 20200509-1 // --- original code --- // string A; // int sz, s[100]; // { // REP(rd_int()){ // rd(A); // if(A=="+"){ // sz--; // s[sz-1] = s[sz-1] + s[sz]; // } else if(A=="-") { // sz--; // s[sz-1] = s[sz-1] - s[sz]; // } else { // s[sz++] = atoi(A.c_str()); // } // } // wt(s[0]); // }