C++ :

#include<bits/stdc++.h>
using namespace std;

int jiahao(char s[]){
	int x,i;
	for (i = 0;i < strlen(s);i++){
		if (s[i] == '+'){
			x = i;
		}
	}
	return x;
}

int num(char s[]){
	int i,n = 0,t = 1;
    for (i = strlen(s) - 1;i >= 0;i--){
        n = n + (s[i] - 48) * t;
        t = t * 10;
    }
    return n;
}

int main(){
	char s[1000];
	char w[1000];
	int n = 0,i,j,k = 0;
	gets(s);
	for (i = 0;i < strlen(s);i++){
		if (s[i] >= '0' && s[i] <= '9'){
			w[k] = s[i];
			k++;
			if (i == strlen(s) - 1 || s[i + 1] < '0' || s[i + 1] > '9'){
				w[k] = '\0';
				//cout<<w<<" "<<num(w)<<endl;
				n = n + num(w);
				k = 0;
			}
		}
	}
	cout<<n;
}

Pascal :

var
  a,s:ansistring;
  i,j,k:integer;
  v:array[1..2000] of integer;
procedure plus(b:ansistring;var a:ansistring);
var
  m,n:array[1..2000] of integer;
  t:ansistring;
  la,lb,len:integer;
begin
  la:=length(a);
  lb:=length(b);
  fillchar(m,sizeof(m),0);
  fillchar(n,sizeof(n),0);
  for i:=1 to la do m[i]:=ord(a[la-i+1])-ord('0');
  for i:=1 to lb do n[i]:=ord(b[lb-i+1])-ord('0');
  if la>lb then
    len:=la
  else
    len:=lb;
  for i:=1 to len do
    m[i]:=m[i]+n[i];
  for i:=1 to len do
   if m[i]>=10 then
    begin
      m[i+1]:=m[i+1]+m[i] div 10;
      m[i]:=m[i] mod 10;
    end;
  a:='';
  if m[len+1]<>0 then
    a:=chr(m[len+1]+ord('0'));
  for i:=len downto 1 do
   begin
     t:=chr(m[i]+ord('0'));
     a:=a+t;
   end;
end;
begin
  readln(s);
  v[1]:=0;
  k:=1;
  for i:=1 to length(s) do
   if s[i]='+' then
    begin
      k:=k+1;
      v[k]:=i;
    end;
  v[k+1]:=length(s)+1;
  a:='0';
  for j:=1 to k do
    plus(copy(s,v[j]+1,v[j+1]-v[j]-1),a);
  writeln(a);
end.
var
  a,s:ansistring;
  i,j,k:integer;
  v,p:array[1..2000] of integer;
procedure plus(b:ansistring;var a:ansistring);
var
  m,n:array[1..2000] of integer;
  t:ansistring;
  la,lb,len:integer;
begin
  la:=length(a);
  lb:=length(b);
  fillchar(m,sizeof(m),0);
  fillchar(n,sizeof(n),0);
  for i:=1 to la do m[i]:=ord(a[la-i+1])-ord('0');
  for i:=1 to lb do n[i]:=ord(b[lb-i+1])-ord('0');
  if la>lb then
    len:=la
  else
    len:=lb;
  for i:=1 to len do
    m[i]:=m[i]+n[i];
  for i:=1 to len do
   if m[i]>=10 then
    begin
      m[i+1]:=m[i+1]+m[i] div 10;
      m[i]:=m[i] mod 10;
    end;
  a:='';
  if m[len+1]<>0 then
    a:=chr(m[len+1]+ord('0'));
  for i:=len downto 1 do
   begin
     t:=chr(m[i]+ord('0'));
     a:=a+t;
   end;
end;
procedure minus(b:ansistring;var a:ansistring);
var
  m,n:array[1..2000] of integer;
  t:ansistring;
  la,lb,len:integer;
begin
  la:=length(a);
  lb:=length(b);
  fillchar(m,sizeof(m),0);
  fillchar(n,sizeof(n),0);
  for i:=1 to la do m[i]:=ord(a[la-i+1])-ord('0');
  for i:=1 to lb do n[i]:=ord(b[lb-i+1])-ord('0');
  if la>lb then
    len:=la
  else
    len:=lb;
  for i:=1 to len do
   if m[i]>=n[i] then
     m[i]:=m[i]-n[i]
   else
     begin
       m[i]:=m[i]+10-n[i];
       m[i+1]:=m[i+1]-1;
     end;
  a:='';
  i:=255;
  while m[i]=0 do
    i:=i-1;
  len:=i;
  for i:=len downto 1 do
   begin
     t:=chr(m[i]+ord('0'));
     a:=a+t;
   end;
end;
begin
  readln(s);
  v[1]:=0;
  p[1]:=1;
  k:=1;
  for i:=1 to length(s) do
   if s[i]='+' then
    begin
      k:=k+1;
      v[k]:=i;
      p[k]:=1;
    end
   else
     if s[i]='-' then
      begin
        k:=k+1;
        v[k]:=i;
        p[k]:=0;
      end;
  v[k+1]:=length(s)+1;
  a:='0';
  for j:=1 to k do
   if p[j]=1 then
     plus(copy(s,v[j]+1,v[j+1]-v[j]-1),a)
   else
    if p[j]=0 then
      minus(copy(s,v[j]+1,v[j+1]-v[j]-1),a);
  writeln(a);
end.

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		int sum = 0;
		String[] b = s.split("\\+");
		for(int i = 0;i<b.length;i++){
			String c = b[i];
			int a = Integer.parseInt(c);
			sum = sum + a;
		}
		System.out.println(sum);
	}

}

Python :

a=list(map(int,input().split("+")))
n=len(a)
s=0
for i in range(n):
    s=s+a[i]
print(s)