/in/foo.cc:5:31: error: 'long long' invalid for 'dp'
 long long double dp[1000][1000];
                               ^
/in/foo.cc:37:47: error: 'long long' invalid for 'dpkk'
 long long double dpkk(long long x, long long y) {
                                               ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:48:35: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
  scanf("%d%d%d%d",&nn,&m, &ss, &tt); ss--; tt--;
                                   ^
/in/foo.cc:48:35: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'long long int*' [-Wformat=]
/in/foo.cc:48:35: warning: format '%d' expects argument of type 'int*', but argument 4 has type 'long long int*' [-Wformat=]
/in/foo.cc:48:35: warning: format '%d' expects argument of type 'int*', but argument 5 has type 'long long int*' [-Wformat=]
/in/foo.cc:52:23: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
   scanf("%d%d", &u, &v); u--; v--;
                       ^
/in/foo.cc:52:23: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'long long int*' [-Wformat=]
/in/foo.cc:75:2: error: 'prlong' was not declared in this scope
  prlong longf("%.3lf", dpkk(ss,tt));
  ^~~~~~