C :

#include<stdio.h>
main(){
	int a,b,m;
	char c,d;
	scanf("%d%c%d%c",&a,&c,&b,&d);
	if(c=='+'&&d=='='){
		m=a+b;
	printf("%d\n",m);
	}
	
}

C++ :

#include <iostream>
#include <cstring>
using namespace std;

//求加号的位置 
int pos(char s[]){
	int k,i;
	for (i = 0;i < strlen(s);i++){
		if (s[i] == '+'){
			k = i;
			break;
		}
	}
	return k;
}

//把s的从下标r到下标k的一段拷贝到w中 
void scopy(char s[],char w[],int r,int k){
	int i,j = 0;
	for (i = r;i <= k;i++){
		w[j] = s[i];
		j++;
	}
	w[j] = '\0';
}

//求两个加数
int num(char s[]){
	int i,t = 1,n = 0;
	for (i = strlen(s) - 1;i >= 0;i--){
		n = n + (s[i] - 48) * t;
		t = t * 10;
	}
	return n;
} 

int main(){
	char s[2000];
	char w[2000];
	char f[2000];
	gets(s);
	int i;
	scopy(s,w,0,pos(s) - 1);
	scopy(s,f,pos(s) + 1,strlen(s) - 2);
	cout<<num(w) + num(f);
}

Pascal :

var a:string;
 t,i,s1,s2,p,d,j:longint;
 code:integer;
 k:boolean;
begin
 readln(a);k:=true;
 t:=length(a);s1:=0;s2:=0;if a[1]='-' then begin d:=2;k:=false;end else d:=1;
 for i:=d to t do
 if a[i]='+' then break
 else begin p:=s1*10;val(a[i],s1,code);s1:=s1+p;end;
 for j:=i+1 to t-1 do
 begin p:=s2*10;val(a[j],s2,code);s2:=s2+p;end;
 if k=true then writeln(s1+s2)
 else writeln(s2-s1);
end.

Java :

import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String str=scanner.nextLine();
		String[] numbers=str.split("=");
		String ab=numbers[0];
		String[] str1=ab.split("\\+");
		String a=str1[0];
		String b=str1[1];
		int a_int=Integer.valueOf(a);
		int b_int=Integer.valueOf(b);
		System.out.println(a_int+b_int);
	}
}

Python :

str1=input()
a=int(str1[:str1.find("+")])
b=int(str1[str1.find("+")+1:-1])
print(a+b)