C :

#include <stdio.h>

int main()
{
	char s1[100] ; 
	scanf("%s",s1) ;
	char s2[50] ;
	int a1[70] ;
	int length = 0, number = 0 ;
	
	for(int i=0;s1[i]!='\0';i++)
	{
		int shi = 1 ;
		int temp = 0 ;
		
		if(s1[i]=='*' || s1[i]=='+' || s1[i]=='-')
		{
			s2[number] = s1[i] ;
			s2[++number] = '\0' ;
		}
		else
		{
			for(int j=i+1;s1[j]>=48;++j)
			{
				shi *= 10 ;
			}
			for(int j=i;shi>=1;j++)
			{
				i = j ;
				temp += (s1[j]-48) * shi ;
				shi /= 10 ;
			}
			a1[length] = temp ;
			++length ;
		}
	}
	
	int sum = a1[0] ;
	for(int i=1,j=0;i<length;i++)
	{
		switch(s2[j++])
		{
			case '*':
				sum *= a1[i] ; break ;
			case '+':
				sum += a1[i] ; break ;
			case '-':
				sum -= a1[i] ; break ;
		}
	}
	printf("%d\n",sum) ;
	
	return 0 ;
}

C++ :

#include<bits/stdc++.h>
using namespace std;  
int main(){           
    string s1;
    cin>>s1;
    int i,t = s1[0] - 48;
	for(i = 1;i < s1.length();i = i + 2)
	{
		if(s1[i] == '+'){
			t = t + s1[i + 1] - 48;
		}else if(s1[i] == '-'){
			t = t - (s1[i + 1] - 48);
		}else if(s1[i] == '*'){
			t = t * (s1[i + 1] - 48);
		}
	}
	cout<<t<<endl;
	return 0;
}

Java :

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String s1 = "",s2 = "";
		for(int i=0;i<s.length();i++){
			char c = s.charAt(i);
			if(c >= '0' && c <= '9'){
				s1 += c;
			}else{
				s2 += c;
			}
		}
		int r = calc(s1.charAt(0)-48,s1.charAt(1)-48,s2.charAt(0));
		for(int i=2;i<s1.length();i++){
			r = calc(r,s1.charAt(i)-48,s2.charAt(i-1));
		}
		System.out.println(r);
	}
	public static int calc(int a,int b,char f){
		int r = 0;
	    if(f == '+'){
	        r = a + b;
	    }else if(f == '-'){
	        r = a - b;
	    }else if(f == '*'){
	    	r = a * b;
		}
	    return r;
	}

	}

Python :

a=list(input())
n=len(a)
s=""
m=0
for i in range(0,n-2,2):
    s=a[i]+a[i+1]+a[i+2]
    m=int(eval(s))
    a[i+2]=str(m)
print(a[n-1])